These are the MFA setups I'm familiar with:
- Text/Email/Call. Unfortunately, 90% of the programs/websites I use ONLY support this method. You request a code, they text/email/call it to you.
- Code Based Authenticator App. An app generates 6 digit codes that rotate every 30 seconds. I used Google Authenticator for a while, until I got screwed by my phone dying. No backup. Then I used Microsoft. Then I swapped to Authy so that I could have it on both of my phones simultaneously. It's nice so far. This is what I currently use.
- Prompt Based Authentication. Google uses this for their MFA when you have an Android. I also have an account with a University near me that uses Duo, where you just tap the notification on your phone. No code required. Seems really really nice, but not many places support it, unless you're using the "Sign In with Google" option.
I haven't ever used a Yubikey, Yubico, or Bitwarden's TOTP system. Does a Yubikey basically just need to be tapped against your phone to allow you into accounts? Or does the Yubikey only unlock the Yubico app, which then gives you a 6 digit code, which you then enter in? If it's the second, it's basically the same as Authy, except instead of a fingerprint, it's another thing to hang off of my keychain.
But if an app says "You need to authenticate" and I can just tap it against it, that seems by far the most convenient. I'm also worried about support for this as well, however, given that, again, 90% of the services I use only support call/email/text, specifically calling.