I'm sympathetic to that argument, but ultimately until Apple supports sideloading more generally, (which is likely never), that lack of control of my device outweighs my concerns with Google's privacy practices.
If they did start doing so, I could switch to LineageOS or even Plasma Mobile, as my phone supports changing the OS without having to exploit a security vulnerability.
Which to be fair, the default in Firefox is the address bar gets sent to the search engine provider of your choice for search suggestions, but you can change the search engine and/or disable that in Firefox for Android, unlike Android Chrome. And on desktop you can separate the search and address bars still.
If you only use a web browser then that's perfect for you. I am a fairly minimalist user and I generally prefer the browser over phone apps but I still use too many apps to list here easily.
For Chrome, you can disable linking browser sign ins to web page sign ins and you can disable FLOC. For mobile - If you don't trust Google, you should probably be on an iPhone IMO. There I use Adguard with Safari and that works just as well as uBlock Origin and better than Firefox on iOS.
I use Chrome all day on desktop systems, but I don't sign in at all and because of that, I just don't do syncing. If I really wanted to do basic bookmark syncing though, I could do that with an extension like xBrowserSync, EverSync, etc. (or even my own). Of course those probably wouldn't sync to iPhone/Safari with some hackey procedure. I don't know if Manifest v3 will stop uBlock Origin because the maintainers have been steadily working on ways to implement the extension with it.
I don't entirely distrust Brave since they've been quick to apologize, explain and/or revert their mistaken behavior. I think they deserve some consideration for the level of innovation they're trying to achieve. For now, Brave is my backup plan for desktop at least, if Manifest v3 breaks everything completely.
Good for me that I pack lightly and I can move to another browser easily or use a mix of them if I wish to.