My main browsing has always been done on Firefox which has sync much like Chrome does, but oh look it's encrypted, forgot my password? Too bad, they're going to nuke my data since they don't even know my password. As it should be. My browsing data being synched is cool but it's not that precious to me, and if it was I would just not forget my password.
Also if I need to use Google services I have a Google container, if I need to use Firefox, I have a Firefox container. Good luck containing Google or Firefox on Chrome that way, and the multiple account containers are amazing for testing multiple user roles on web development projects all on one browser with multiple taps opened.
In my case, I don‘t switch to Firefox because they don’t support AppleScript and it’s a feature I use every day.
Less than an hour ago, on another HN thread, I saw another macOS user claiming they won’t switch to Firefox because it doesn’t support Keychain.
Every time there’s this conversation, I see a bunch of macOS users complaining about performance.
In sum, a bunch of users (particularly macOS users) don’t switch to Firefox because it plain sucks for their needs.