Firefox really needs to implement two features:
1. Cookie Auto-Delete (see https://github.com/Cookie-AutoDelete/Cookie-AutoDelete/wiki/...), where cookies and local data are automatically deleted some time after closing the tab. You can, of course, whitelist Websites to exclude them.
2. Firefox multi-container extension, to assign some websites (domains and subdomains) to a container by default so that you can visit some specific Google sites without being logged in (e.g Web search, News, Maps…) but still open Gmail and be connected to your account.
You can make this more intuitive and combine that in a single button: "Do not forget. Optionally, open website in <container>".
This would drastically level the playing field, as one can continue to use some Google/Apple services for work (e.g Play developers console, Google calendar…) but all visit to other properties would not be tracked. No need to switch between browsers, profiles or containers, this is automatic.
I've been using this set up for years now, and it works perfectly – just add uBlock and I don't care about cookies, and you'll ever see an ad or a cookie prompt ever again. Perfect.