It's not their area of expertise.
Animojis, on the other hand...

Givin' enough time, Apple could do it anything with LTE themselves, but they don't wanna go into that relm, which means they gotta put up with these issues from other companies they and deals because its easier to license separate companies already in the field, but at a cost of trusting.
Seems Apple's been falling into this time and time again.