Usually, it's the free services that throttle your usage in these ways. Some paid services will offer a trial, where you can transmit up to a certain data cap before being asked to sign up as a paying customer. That's actually pretty cool, because it gives you a chance to try out the performance of their service before paying, but it also gives the vendor a chance to make the money necessary to operate the service.
That attitude to the safety and privacy of personal data creates an enormous online security risk. Public Wi-Fi networks, which are ubiquitous and convenient, are unfortunately also highly convenient for attackers looking to compromise your personal information. How do you know, for example, that "starbucks_wifi_real" is actually the Wi-Fi network for the coffee shop? Anyone could have created that network, and they may have done so in order to lure victims into disclosing personal information over it. In fact, a popular security researcher prank is to create a network with the same name as a free, popular service and see how many devices will automatically connect because it appears safe.