Typical Apple, trying to force some technically-superior crap down our throats rather than attempting to play nice with the rest of the world. Nobody else uses HEIC. I daresay most people don't even know what it is. Why not play nice with others by default!?
Blaming Apple for this is ridiculous. It is trivial to validate input, and it is trivial to do so in a way that the iPhone will upload JPEG by default.