Being replaceable tends to make work less satisfying. All the places I've worked at that followed your advice had the most churn and the least productivity/ROI on engineering $ spent.
Being replaceable tends to make work less satisfying.
In my experience the opposite is true. My personal goal on any project is to make myself replaceable. There's nothing I find more tedious than having to work on the same thing for years because no one else can take over from me.
You’re talking about something else, where you are an key employee building a valuable system that doesn’t need you. The other person is talking about a company hiring you to fit into a system that never needed you.
> My personal goal on any project is to make myself replaceable.
So you admit that you aren't replaceable? If the company mandated that you should always be replaceable then you wouldn't need that goal, it would always be fulfilled. And working in a way that makes you always replaceable isn't fun.
Edit: What we learned from your comment is that making yourself replaceable is fun, but being replaceable isn't fun, since as you say you work to become replaceable so you can start working on something new rather than to stay replaceable forever.
I would hate to be stuck on the same product or set of features, but I very much enjoy getting to a point where I know all of the systems, how they relate, and roughly where all the functionality lies and who's worked on what. It takes a lot of time to develop that experience and it's so valuable, and it seems so strange that companies don't want to select for this and we're dominated by a culture of job hopping every 2-3 years because it's the only way to maintain appropriate pay. Then companies wonder why everything is over budget and never on time
I think like most things there is a balance. The sweet spot may be I can go hard on the project but if I feel like I need some time off - there is the ability to step back and have the work continue.