Let's not go into hypotheticals about what might happen if google started... what, inserting spyware, basically, into their own open source browser engine?
Chrome and even Firefox have already begun political policing of their browsers (https://reclaimthenet.org/google-chrome-web-store-bans-disse...). The next step seems like it’ll be forced curation of the web or blocking of IP addresses, since they’re already knocking on that door.
They banned a sleazy-looking extension from their extension stores. That's a far cry from "forced curation of the web or blocking of IP addresses". And, if that happens? Someone will just fork the browser.
Which they certainly have done in the past (albeit,usually for really good reason. Google is a bit in a damned if you do damned if you dont position)