You could have more the one backup. You could split them with shamir secret sharing, if you want to get fancy. You could take an old iPhone, or reflash an old retired Android with LineageOS or GrapheneOS, and keep it in a safe but accessible place as fallback TOTP device.
Have as few or as many as you want. If you want to keep 0 copies and then lose access to the one working device, that's on you. It's no different from any other password.
The one-time-use emergency codes are stupid. The seed value is all you need, and it's just another secret like the password. You can copy it in any form you want, and use it on a new device or on 13 differnet current devices, whatever.
The danger from losing the seed value is no different from the danger from losing your password. The difficulty of keeping and re-using the seed value is also no more than for any other secret or password.
The totp apps and sites that use them create a problem where there isn't any by simply not telling you to save the seed value. It's perverse, becauyse they do give you the seed value. They have to. They show it directly to you because it has to go through you to get from a web site into a totp app.
That might be automated by a qr code, but they had to display the qr code to you, and you can just as easily copy and read that qr code as the totp app can.
It's effortless to save it along the way. But they just don't tell you what it is and don't tell you to keep it.
THAT is the only reason you end up screwed later.You were essentially not told what you were holding briefly, and told to discard it, but it's actually the keys to your kingdom and you can just, not throw it away.
Or do throw it away and then try to make silly arguments about how you're locked out.
