My heart went in my throat when I read your title, I assumed the worst, meaning crypto keys, I'm glad it was just your house keys.
A “decentralized authenticator application” is a good idea. Make things simpler, yet more secure.
I struggle between attaching assets to a key that I own but I could lose; and attaching assets to my identity which I own but I have to trust that the "custodian" does not lose to somebody else or locks me out.
As I get older, and I start to forget things, I'm hoping there's a solution to where I can have the best of both worlds. If I lose my keys I can recover them with my identity without the other party or app having access to those keys. I think safe deposit boxes work from that concept, but it can be physically inaccessible. Maybe a biometric safe in one's house or 24/7 accessible secure location.
I would be pretty annoyed to lose keys that matter :)
There are always security holes if one kind or another, but having a few options allows for people to choose what they are willing to risk. The problem is, most people don't understand enough to evaluate the risks well, especially if they are used to having a platform look after everything for them.