As long as Firefox keeps up with the standards treadmill, I could be the only person using it, and it really wouldn't affect me any. As of right now, there are vanishingly few sites that earnestly work differently on Firefox than on Chrome. Significantly more sites arbitrarily block non-Chrome User Agents, but that's trivially avoided by just serving a Chrome UA on Firefox.

Which makes it trivial to switch. There's really no justification for sticking with Chrome. Switching to Firefox takes about a minute, you can import all your saved logins and bookmarks, and then maybe spend a whole whopping 30 seconds adding Ublock Origin. Complaints about Chrome amount to "I am too inconceivably lazy to spend 90s switching to a browser that doesn't hate me".