I don't see people mention this enough, but iCloud Keychain generates TOTPs. I've been migrating all of my accounts slowly to just use the built-in Apple Passwords functionality.
In Safari, right click on TOTP QR codes.
In Safari, right click on TOTP QR codes.
BTW, there's a hack you can do to create an iOS Password app in iOS 17 and below by using Shortcuts to launch the deep linked setting directly.
How much stringency does a code/platform change get at Authy vs Apple? However, once you are in the Apple walls, they are just as ruthless at keeping you locked inside, which is why I try to minimize my dependencies where possible.