Real cross-device passwordless is likely coming in the next year or so. WebAuthn/Passkey is in its 3rd public working draft[1] and once finalized, we'll likely start to see it across sites. Most devices, browsers and managers have added or are adding support for it: Apple, Microsoft, Google, Auth0, Duo, 1Password, etc. If you haven't seen it, Auth0's demo is helpful[2].
As a side note, if you want to try out passkeys now and don't want to tie it to your device, I would like to plug my solution, Bulwark Passkey (https://bulwark.id). It's open source, allows you to export your credentials if you want, and supports all browsers since it emulates a virtual USB device.
https://mjg59.dreamwidth.org/62175.html https://news.ycombinator.com/item?id=33810984
What downsides are there? E.g, will it work on rooted phones? Will apps start adding mandatory pin numbers on top (like they do for biometrics), or will Google/Apple's app stores disallow it? How do I "log out" to avoid tracking without being implicitly logged back in? What happens if I routinely wipe my browser settings? Can I use some other person's computer to login in a pinch? (Such as when my phone is off network?)
In principle, browser and os vendors could work through all these "niche" use cases, but I'll be pleasantly surprised if they actually did.
Any ideas? Thanks!
Edit: I was able to reproduce the issue; it looks like WebView2 (which Bulwark Passkey relies on) is already installed on Windows 11 but not on Windows 10. I released a new version on https://bulwark.id that has that WebView now embedded in the app itself, would you mind downloading that and seeing if that works? Thank you for the report!
Personally, I think that the main blocker for adoption of passkeys is ease of use, as if you can't transfer your credentials either off of your device or away from your Apple/Google/etc account, then I think it will be a hard sell to users.