Because so much of the 'developed world' accesses the internet through old phone lines, the ISPs have to throttle and cap because of the limitations and because of the high price charged by monopolies for data transfer.
If we had real fibre networks and peering there would be no need for any such management, as it would all be cheap and plentiful and the internet would just work.
As it is now, it is in the control of the wrong organisations, who will back governments and try to break it in order to make it fit their plans. We have to resist, and keep our internet open and free.
Solve this simple math problem and enter the result. E.g. for 1+3, enter 4.