don't lose or break your phone....
What is the other one doing in the gym, unprotected?
Oh, they're stored online? There goes your entire "secure enclave" argument ;-)
Not saying Apple is doing that now, but I imagine it's not outside the realm of possibility.
Also I have recovery keys for the more important accounts printed and stored in a safe box.
But anyway, somebody could cut off your access to Dropbox, but it’s less of an issues since you have a backup.
Which I'm glad to know you can at least do with Keychain [1], although I use Bitwarden myself.
[1] https://support.apple.com/guide/keychain-access/import-and-e...
It’s useful even in non-multi-device scenarios.