Their Pixel line hasn't dominated the market by any means, but has also done well enough that they can at least claim to some extent that they don't "need" the other manufacturers. Of course they do, but they can use "whatever, we'll just make $COOL_THING a Pixel exclusive and leave you behind" a threat with teeth. They actually do sometimes make features Pixel exclusive (sometimes just for a limited time), and that seems to be working out ok for them.
Similarly, Apple made a lot of concessions to the wireless carriers back in the beginning, but I'd wager these days they've also clawed back most of that control. If Apple tells their customers, "we wanted to give you this cool new feature, but Verizon wouldn't let us", that will not go well for Verizon.
So I do agree that there's some compromise, and Google (and Apple) don't get to do literally anything they want, they are in a much better position to control their ecosystems and dictate terms than they were back when they started.
What concessions would those have been? The way I recall it, Apple in the early iPhone years would always favor retaining control over the phone experience over carrier reach, so they were available on very few carriers initially (especially compared to Android), but would not make concessions to them. Eventually, iPhones became a must-have item for carriers, so they all signed on under Apple's terms — and nowadays, unlocked phones are mostly the norm anyway.