Not that seamless if you do not want to be locked into a single platform, though. This is what the article mostly talks about.
Why are you locked into a single platform?
I use bitwarden, Google and a yubikey for passkeys. Which of these am I locked into?
Apple has offered an “iCloud for windows” app for ages that literally syncs your iCloud Keychain (passwords and passkeys) to a windows box where you can use browser extensions for chrome, edge, etc.
You’re still not platform locked…