If you are on iOS, I recommend using the following:
It’s open-source and recommended by PrivacyGuides.
I’m on Android, where that’s also an option I believe, but I’m using Aegis.
Bitwarden also came out with an open-source MFA app, though it’s a bit new so I’d recommend waiting to see what folks say about it.
Raivo uses to be a good (and the only decent) choice for iOS but I believe it was acquired by an insidious company.
Yes it only works on Pixel phones. For other devices I recommend looking at DivestOS, CalyxOS, and LineageOS - in that order from best to worst insofar as de-Googling and privacy are concerned.