I tried this recently because ideologically I agree. But the small issues build up and make me less productive.

For example, if you use a U2F key, you need an extension for that to work - and that extension doesn't work with FF 57. I honestly don't remember the last time something broke with Chrome.

Or smaller things, like the fact that I can't use the keyboard to manage bookmarks (in FF on macOS, backspace doesn't delete bookmarks).

But the worst is in FF, Ctrl+Shift+N isn't new incognito window, it's restore the previous window. Years of muscle memory don't go away overnight.