Earlier quoted context omitted.
The Apple keynote made a pretty big deal about innovations that enabled the LTE features. They didn't explicitly say that those were Apple innovations, though.
Compare the size of either Apple Watch to a Samsung LTE watch - even the larger 42mm Apple Watch is comfortably smaller than the Gear, and the 38 makes the Gear look like you're wearing a yo-yo on your wrist. That size/battery life stuff is what took all the work, and why Apple waited until it was able to ship without the compromises.
The size increase in Gear S3 was more dictated by fashion than necessity -- after the Gear S2, Samsung had market data that their primary buyer group favors larger watches in general, so they decided to bulk it up and increase battery life. (A lot of men actually like that "yo-yo on the wrist" look, for reasons I don't entirely fathom. I guess it's sporty.)