Google controls Chromium to the extent they can impose changes like manifest v3 and while some forks like Brave will try to circumvent such changes, it will eventually become too costly or incompatible to maintain.

It is kind of the same daydream as the Windows 11 debloaters have that if they just keep doing that, everything will be okay. That is until Microsoft implements features they can no longer fully disable, like recall, or just exercise their control to revert any changes at will.