One early example of just how much a wholesale-based business model can collapse was what happened to the dial-up internet access industry when the switch to broadband happened.
In the dial-up era, ISPs did not need to buy access on a wholesale basis from the carriers. They were able to use any available facilities and then just sell the internet access as an app that rode on the existing network.
The shift to broadband destroyed the business model, as for the first time, ISPs had to buy wholesale access from facilities-owning firms. That destroyed the business model.
The same thing happened when wholesale tariffs were changed in the U.S. “competitive local exchange carrier” business. CLECs rented access and full services from telcos, and then resold them to consumers and businesses, on the strength of wholesale discounts of about 40 percent.
When the rules changed, and discounts narrowed, the consumer services business model evaporated.
In the mobile services business, we might see something similar, if unlimited usage plans remain the industry staple. The reason is that mobile virtual network operators are likely to find they cannot maintain a business model when they must buy wholesale access that allows a retail unlimited offer.
It has happened before, and might well happen again. At the end of the day, in competitive markets, facilities ownership is the only way a competitor can control its own costs, long term. Cable executivs call that "owner's economics."