Realistically the threat we care about is others leak your password. So it doesn’t matter.

If you have a setup where your password vault is at risk then yes it’s a bad idea.

I suppose there is a certain level of risk but that's true with any solution. Passwords generally don't get changed very often and that's usually what's going to be nabbed up by somebody that in your username of course. With TOTP, putting that in bitwarden means that in order to get access to whatever account, they first have to get your credentials which they probably got from a dump filled with a bunch of other credentials, then I'd have to figure out that you're using bitwarden was your be no sign that you are. Then they'd have to actually get into your bitwarden which if you're doing it properly should be difficult. And if the login to bitwarden is completely different than the account are trying to get into it's basically invisible to them.

The only way I see bitwarden being the weak link, is 1. Someone has physical access to your devices and they know what they're looking for (in this case it's probably a roommate or family or friend, someone that you trust but probably shouldn't). 2. Bitwarden gets compromised (which is an impossible but it is probably more difficult because it is an open source thing). 3. You go to shady website and install shady stuff and that install some sort of keylogger, or something else that shows what your system has (hell, Microsoft recall would actually fall into this category) and a back actor sees that you have bitwarden and how you log into it. But that being said, 1 and 3 aren't necessarily stopped by having a password manager solution and the separate MFA solution... But it could slow them down.

But physical MFA isn't impervious either. I don't recall if it was yubiki or Google's Titan, if I remember back years ago one of them had a problem.

Not if you protect the master key with MFA, like a yubikey. Then it's cryptographically secure for quite a while..at least until quantum computing is affordable enough to be used against your data. Or the database and your yubikey and yourbpassphrase are compromised

You've got a good point. I wonder if this an example of a trade-off between convenience and security. If you're logging in and you get an MFA prompt, a Yubikey has to be physically searched, while Bitwarden or Proton Pass only have to be clicked. A Yubikey can only hold a limited amount of accounts, while Bitwarden or Proton Pass could hold many more. Of course, a Yubikey could be used as MFA for Bitwarden or Proton Pass, but that would create a single point of failure and reduce factor separation (which I think is your original point).

While I posted a Bitwarden or Proton Pass recommendation of sorts, I genuinely wonder if it's advisable to not use MFA at all if the factors will not be separated. Or, perhaps, the best security solution is the one you'll actually use. I guess the answer is the good ol' "What's your security model?"

Possibly not now that it saves your codes to your google account (it didn't use to), but it made me uncomfortable for my password manager to have both factors together to log into something like my bank or root AWS account. So you'd have to compromise two different places to get in

Technically they export a json file (with a different extension). But you can move to another tool with this.