Maintaining passkeys
The use of Passkeys took me be surprise but thankfully I use Bitwarden to manage all of my passwords so when prompted by a website to store a passkey, Bitwarden captured it for me.
I use it on several Windows machines with Firefox and Android with Firefox.
I have properly secured my access to Bitwarden with physical keys and second factors, so I'm happy to delegate most password storage to it.
So if this a problem your trying to solve there are solutions out there. Bitwarden is 40USD per year for a family account (5 users) which is well worth it IMHO. It mostly works for prompted passwords, but it's not perfect and sometimes auto fill fails and you must copy/ paste in the information you want.
However, I find that even this small step to take is too much for the family and so I occasionally nudge them into using it. We'll see if it catches on....