It is conundrum that passkeys were designed to help the majority as they are frictionless (like passwordmanagers etc) but fail in reality.
Even those that have 2 devices they don't have them all the time.
Another overlooked issue is that some banks etc don't allow for 2 devices as login or 2FA. Even if it allowed one needs to keep the spare device always updated. Either Govt needs to build a common API that one can use directly through google pay or apple pay - so that only one app is needed to be kept up to date.
to be honest, I wouldn't mind if google/Apple can take all my private data and passkeys hold them - but at least then if I lose the phone - and I show my ID they should allow me to setup my new phone. But that is also not possible. (I am discounting the awful AI bans)