cmaier is correct.
FaceTime is not new.
Apple has had plenty of time to create a Windows desktop application (like iTunes) and even a native Android app yet have shown zero inclination in doing so.
Another option for Apple would be to create a plug-in that runs in a web browser (like Zoom).
And yet another possibility would be for Apple to open up the FaceTime protocol to third-party developers. Again, Apple hasn't done so over all these years so it is unlikely it will ever happen.
Apple is content in letting FaceTime users only communicate with other FaceTime users. That cripples FaceTime's adoption but Apple doesn't really care, even in the work-from-home COVID-19 era.