Ethereum actually has almost no client diversity. The vast majority of nodes run the geth client (go).
Regarding the security aspects of L2s: they will of course not be anywhere near as robust as ethereum itself, but over time they’ll get better. However, they also don’t need to be as robust as ethereum given they effectively benchmark against the ethereum chain so while things could go wrong, the amount of damage will be very contained and as the ethereum mainchain scales the damage radius becomes ever more contained. Finally the bridges that are being implemented to move assets from ethereum to the L2s can implement emergency withdrawal mechanisms which allow users to get their assets out even if things go wrong.
Not perfect, but the tradeoff seems reasonable to me given the performance enhancement and the diversity of functionality that can be offered via many different environments.
Disclaimer: I’m quite possibly biased due to my company working on L2s.
Re: GP comment - From a "trust" perspective, there is a distinct difference to call out between the integrity of data on the platform, and the trustworthiness of the platform itself (i.e., the ability for centralized control of all data)
In an instance where an L2 is compromised, the potential impact is limited to the integrity of data that individual L2 was contributing to the overall platform.
Those transactions which demand absolute integrity will naturally tend to occur on L1, for this reason. Risk mitigation strategies will develop for those operating on L2 + bridged chains.
>In an instance where an L2 is compromised, the potential impact is limited to the integrity of data that individual L2 was contributing to the overall platform.
I think distinction is only meaningful as long as L2s remain a niche curiosity while the majority of transaction volume resides on L1. If the L2 plan succeeds and almost all volume passes through an L2 and one of the major L2s has a bug like in this post, then a large fraction of all ETH could end in the hands of hackers.
The ledger would accurately reflect the moment that a bad actor lifted e.g. 5-10% of the ETH supply off an Arbitrum or StarkNet bridge. Technically the L1 is uncompromised but a lot of money would be "redistributed".
Certainly a possibility, but this is one reason I’d be inclined to believe there will be some significant demand for direct L1 transactions, and a diverse set of L2 layers.
Are you envisioning homogenous L2s, or those more specialized in nature? I envision the latter, which would mean the number that any individual entity is exposed to would be limited.
But your point does highlight the UX implications of too much fragmentation, and it’s a worthwhile consideration
What kinds of transactions do not demand absolute integrity, but still make sense to use a blockchain for? (I don't know much about these sorts of things, I'm actually asking for examples)
Security of zk rollups may be sufficient for a lot of activity - trading, DeFi, games, art, DAO/access tokens, escrow, crowdfunds, all the web3 stuff.
The L1 may eventually be a primary settlement layer for protocols like zkSync and StarkNet (and any other protocols and rollups built on Ethereum L1). At some point it may not be common for users to interact with L1—ie. users of Argent and Sequence wallets may only be holding assets on L2.
zkSTARK/SNARKs has pretty dramatically changed the L2 landscape and new direction seems to be moving away from optimistic rollups like in the OP. This is just my understanding, somebody please correct me if I’m wrong.
On one hand you have a complicated protocol that doesn't really use cryptography and that has the user (you) monitor the blockchain for a week to make sure their transfer was processed correctly (otherwise my understanding is that you have to create a fraud proof, send it to the chain, otherwise you will lose your funds).
On the other hand you have a cryptographic proof of a few kilobyte that proves that some program correctly validated and applied the state transition of thousands of transactions.
As a zkSNARK cryptographer, efficient cryptographic proofs are incredibly complex pieces of technology that still have a ways to go before they can match the speed of native execution. Both approaches have pros and cons.
I gotta admit I don't know what 50% of the words there mean, but it surprises me to suggest that "absolute integrity" would not be required for trading, escrow, DeFi, DAO/access tokens.
Makes sense for games and art (but then I wonder what they are doing using a blockchain in the first place).
zk rollups tend to inherit most of the security features of L1[1] but with some trade-offs.
The trade-off is basically scalability (and thus fees). If the L1 network is so highly congested that each transaction costs $100 or more in the future, a scalable zk rollup that achieves about the same level of security at the cost of < $0.001 may be worth these tradeoffs.
This turned out to be longer than I intended. Apologies.
I view Ethereum as a value network, connecting disparate sets of transactional use cases around a set of core services (like Address, asset records, and transaction functions)
To believe that blockchain makes sense for assets which do not require absolute integrity, you'd need to first accept that there are valuable use cases which having an asset management & transaction layer (L1) serves.
If we establish that there are valuable use cases that attract asset management to L1, at a certain point network effects begin to take hold, and the system becomes "top of wallet".
There are parallels in how you manage traditional finances today - Even if you have multiple bank accounts and digital wallets for USD (e.g., a Chase account, Cash App, Venmo, etc.) you're likely to mentally consider one of those your "primary" account. The important one. The main difference in the value network of Ethereum is that the primary account can aggregate the assets that are managed/transacted through L2 solutions. The L2 solutions leverage the core "identity/asset mgmt layer" of L1, but serve use cases that don't justify the cost of development/operation/transaction on the main layer.
To connect this analogy to the original question, let's imagine that your Bank Account offered direct integration with each of the other accounts you manage - Capturing every asset you held, including the 124 gold you still have on your World of Warcraft account from a decade ago. If the 124 gold were to somehow disappear due to a bug/hack/other integrity issue, your bank account would reflect that. But the important stuff would be there.
TL;DR - If commerce generally moves to blockchain systems at significant scale, there will be an acceptable level of failure on L2 systems to support the convenience of aggregating up asset mgmt alongside the important stuff.
This does a good job of answering what kinds of transactions you don't care about, but not why you want them to be on a block chain.
The usecase given agregating those assets by the wallet has two problems:
1. You can have many wallets
2. Not everything associated with the wallet has to have it's transactions tracked on a block chain
All you need is one more column in the wow database, and you can pull up your wow assets with your wallet without them being on the L1 or L2 chain
I suppose that’s fair. You could theoretically argue for some “integration” between an off-chain centralized database and on-chain wallet - but unless it were just an untrusted pointer, there would need to be some asset managed from a contract to serve as a “proof” of sorts.
If you’re questioning why people would prefer on-chain vs off-chain games, I wager there’s something appealing about the “decentralized” nature of the system that attracts people to on-chain games - and I put decentralized in quotes because it’s not always certain that’s a promise always delivered on, but it’s where the appeal is derived from.
Regarding your other notes - 1. Same theory applies though. One wallet is often seen as a primary wallet (hot) that manages public facing assets - e.g., registered ENS domain, an NFT, etc. 2. It’s certainly not required that all associations live on chain, but if you want core services and verification of ownership, it’s mostly on/chain or bust.
execution node (ETH 1.0) diversity is important, but actually more important moving forward is the consensus (beacon chain, fka Ethereum 2.0) diversity. The crawled data here shows that Prysm has almost 2/3s of that: https://migalabs.es/crawler/dashboard
Regarding the security aspects of L2s: they will of course not be anywhere near as robust as ethereum itself, but over time they’ll get better. However, they also don’t need to be as robust as ethereum given they effectively benchmark against the ethereum chain so while things could go wrong, the amount of damage will be very contained and as the ethereum mainchain scales the damage radius becomes ever more contained. Finally the bridges that are being implemented to move assets from ethereum to the L2s can implement emergency withdrawal mechanisms which allow users to get their assets out even if things go wrong.
Not perfect, but the tradeoff seems reasonable to me given the performance enhancement and the diversity of functionality that can be offered via many different environments.
Disclaimer: I’m quite possibly biased due to my company working on L2s.