For cell at least there's some reason for it, as RF bandwidth is essentially a shared resource, kinda like if all the phones are on a hub. That said, the current caps on cellular are ridiculous. They should be in the 100's of GB, not MB. Though really they could easily just offer unlimited but just have some kind of global throttle as the tower gets too busy. Voice and texts should have priority over actual data, so when it starts to get congested data would start to either cut out completely or just go to really slow speeds. People might complain that FB is slow, but it's better than getting a bill for like $250,000 because some rogue app you were not aware of decided to start chewing bandwidth while you sleep.