It’s a legit possibility that “FaceTime” in the future will be super low bandwidth because the phones on each end do local animations of a deepfaked/skinned model to match live capture rather than transmit high resolution video.

This is actually how FaceTime works on the Apple Vision Pro. Though that’s because your face is covered by a giant headset.

We can already compress video massively, enough to video call on crappy mobile connections without much care. I can’t imagine network connections would get worse in the future so it wouldn’t seem like there would be a need to compress further.