In other words, Google is a monopoly. Their strategy is to monopolize markets and charge artificially high prices for advertising.
It's a weird sort of monopoly though, their users can go elsewhere, but their users are not their customers. Their customers are advertisers, and they are basically forced to use Google.
In any case, what you wrote seems to confirm that Google is advertising company rather than general internet service company or web search company.
Edit:
in any case, Google, while having smaller revenue and market cap than Apple, seems to be able to put squeeze on the competitor exactly because it can leverage having large share of (advertising) market against Apple's medium share of (consumer electronics) market.
It's a weird sort of monopoly though, their users can go elsewhere, but their users are not their customers. Their customers are advertisers, and they are basically forced to use Google.