Bitwarden provides a facility for MFA. Though there's an argument to be made against eggs + baskets. It might defeat threw purpose a bit.
I use Aegis which is opensource and easily encrypted and backed up locally.
Saved my ass where I accidentally deleted my 2FA for Bitwarden, thus locking me out in circle of shite. Aegis allowed me to roll back and pull in that one missing key without having to redo a load i'd made since the last backup and all was good.
Yea, I think everyone that is saying Bitwarden supports 2FA is missing the point of 2FA. You don’t want it to be in the same place where all your passwords are, otherwise if someone gets access to your passwords they essentially can prove they are you.
That being said, I use a mixture of Authy + Bitwarden. Bitwarden for sites that require it but aren’t really a priority for me to keep separated, and Authy for 2FA codes that I prefer being separate from my passwords.
I personally think it's best to keep 2FA keys out of password managers.
The whole point of 2FA is to have a seconds factor to authenticate you.
If someone gets access to your password vault with your 2FA keys, they have access to all of your accounts - 2FA protected it not. If you keep the keys in another app, they cannot access your accounts nearly as easily.
Google Authenticator is just a UI for TOTP which is standardized. I've used Authy for many years. But there's also many many implementations: https://search.f-droid.org/?q=totp&lang=en
KeePass. You need TOTP plugin for Windows and there is a nice Android app that implements it out of the box. They also support Steam OTP, though it's a bit hard to set up.
There is also KeePassXC if you want a cross-platform client, but I have no idea how good it is as I never used it.
Idk about the central instance, but I use my bitwarden (specifically vaultwarden) instance for my TOTP keys. I can just autofill and then it copies the current TOTP key and i can paste it in to log into whatever i'm logging into!
If you're interested in moving away from Google Auth, look into a password manager for added security. Along with storing passwords, managers like 1password support 2FA and store your information in the cloud using a Zero Knowledge model. I've been using it for a few years and have not had any reason to use Google Auth.
I personally use yubioath for anything that doesn't support yubikey. Sounds like that isn't a solution for you (maybe a totally different, open source hardware key?).
I'd recommend against putting your 2FA inside bitwarden. It's not a very good second factor if both factors can be exposed by getting into your bitwarden.
It not that isn't absolutely not a solution, but more that I want to split work and life, and I know I could have some remarks if my collegue see the app of the keys used on my not work phone and I could just avoid certain discussions
Just plain old TOTP? A lot of applications support it, you could even implement one yourself if you are brave, as the algorithm is very simple (don't do that): https://datatracker.ietf.org/doc/html/rfc6238