Lots of people are grandfathered into unlimited data plans from their cell phone carriers, unfortunately, finding a true unlimited data plan these days really isn't that easy. Most of them have some kind of strings attached, such as soft caps that start to throttle your internet speeds after you use a certain amount of data.
But, why do carriers do this? Is it all about the money? Or is there another reason?
For the most part, it's a way to monetize their network by making the customer pay more to use more, but there are a direct few users who tend to over-use the unlimited data plans for things they're really not supposed to, such as for personal hotspots that replace their home internet plans outright.
On the other hand, people who stream video constantly, and use upwards of 200GB of data per month, are hogging up all of the bandwidth that can be utilized to provide other smartphone users with a blazing fast internet experience.
Each time someone gets on and starts using cellular data in this way, they take up a lot of that limited bandwidth, and carriers are faced with the goal of better optimizing their data network to handle more requests at a time, which requires expensive research and development.
So perhaps carriers truly do have a good reason to eliminate those unlimited data plans, or perhaps there's a solid explanation for why you have to pay extra when you reach certain data caps. Just think about it... you're not the only one using that cell tower, and when you're the one abusing it, you tend to be blind to how it affects other users.