Thanks for your input. Obviously i did, i just did not expect loosing my sim card in the first week. My bank changed my account to paper TANs and i hope they will still support that for a while, after that i could probably opt in to carry a additional card reader device and auth that way.

Obviously i am a edge case. But while trying to fix my issue i encountered several companies who never even though about this kind of case. This is really all i want to reach here. Make people, especially those who implement such systems, think about a alternative or at least a proper workflow to fix issues like this.

I have access to everything i need now, its not like its unsolved and i am crying for help. It sucks that i cant enable 2FA on several sites, but well, for now i have to live with that.