The downside of 2FA: you basically never change your phone number. Therefore giving it to someone to log in is the best way to track your identity across all services. And on top of that you only have one of them, so you are always identifiable. They don’t necessarily have your name and interests attached, but it suffices for advertising, tracking, etc.
Personally, I use it all the time for its added security but it’s suboptimal if you want to maximise privacy.
Tor usage for everyday stuff increases anonymity for everyone, since Tor lives and dies with “generate as much data clutter and mess as possible”, so every user helps making it more secure for everyone. But, as you said, it’s sloooooow.
That said, quite a helpful article for most people out there.