Steve Jobs in his announcement of FaceTime back in 2010 said it was gonna be open-source. That never happened.

They wanted it to work with a peer to peer protocol, but then got sued by a company I can’t remember, so they instead relied on relay servers.

Sure, you could use FaceTime on Android and Windows (and I guess Linux and FreeBSD), but you have to visit a specific website and have an invite link from someone who has an Apple device. Not very open-source if you ask me.

Walled gardens make money, and add frustration.