This also boosts value for ios users more than the rest. It means an ios user can facetime anyone rather than only ios users while an android users still has to rely on an alternative solution.

I worry that my contacts could feel insulted if they find out I'm contacting them via this sort of "don't call me" communications channel.

Well it sounds like they will send you the link between another communication channel. So you can always respond there and send your own video call link (using another service).

I’m sure if they could kill global phone networks with FaceTime for everyone they would, but I think that they’re solving spam by blocking any device that spans using a serial number or secure UUID or something that iOS can’t fake, rooted or unroofed — but their web solution can’t access such data to provide a hardware-baked identifier to ban for spamming.

Theory confirmed:

> Non-Apple users can join a one-on-one FaceTime call or a Group FaceTime call, effectively making FaceTime a more platform-agnostic video service that is no longer just limited to iOS users. You do, however, need an iOS user to start a FaceTime call and send a link.

https://www.macrumors.com/2021/06/07/facetime-pc-android-use...

> Apple announced that FaceTime is going to be available on the web so users can call in from Android devices and Windows PCs

From the article.

“call in” means an Apple user has to initiate the call, as GP stated.

That implies, but does not guarantee. It’s my best guess, not a certainty.