They lost the ability to go into a store for support, lost phone support, and get deprioritized but they use it for personal use and don't care.
I use my phone to run a business. I will spend the premium to have the best service I can afford to run my company. I pay for the top plan on Verizon as a result.
Choice is good. An MVNO is not for everyone but it is a much lower cost option for those who want the downsides.