Windows can run APK files natively these days: https://learn.microsoft.com/en-us/windows/android/wsa/

ChromeOS runs Android apps as well.

Apple has Mac Catalyst (https://developer.apple.com/documentation/uikit/mac_catalyst) which may just work with this wrapper.

Linux can run Android through Waydroid (though doesn't work as well as on Windows).

PWAs can be installed to desktop on practically any browser that isn't Firefox to make them look like native applications with icons and protocol/share handlers and all.

So technically, it's cross-platform as in "mobile apps that will work on desktop if you like a terrible experience"

I suppose on desktop (windows, linux, macos, ...) you could use the rust component as a normal library without the need of special stuff like on android ios and web

Apparently yes. But we have installable PWAs, so…