[nunez]

Eh, I don't know.

Many of the password storage services support passkeys (which are crossed platform). You can also use a Yubikey as a passkeys.

Regardless, most people will store their passkeys in their iCloud or Google accounts, and given that those certs live in secure enclaves, this is way more secure than writing passwords everywhere or using SMS for 2FA (especially given SIM cloning attacks and the whole Chinese hackers in our networks thing)