I hope one day that Matrix becomes this, but it doesn't seem likely. Fingers crossed Proton at least does it one day.

Using a cross-platform password manager, like Bitwarden or 1Password, would work in your case.

how do i log into passkey protected Paypal on my nintendo switch? how do i log into my Sony PlayStation account on my PS5?

This is being worked on: https://fidoalliance.org/fido-alliance-publishes-new-specifi...

Absolutely, everyone I recommend BW to appreciates the notes feature as well - it's handy to have a place to jot down important things that aren't log-ins!

Archive link: https://archive.ph/eBFsu