There is a solid, technical problem with VPN usage on such a massive scale. Carriers, like T-Mobile, can arrange traffic exchange with big content providers. Majority of traffic generated goes to a handful of providers, like YouTube, Netflix, Facebook. It's not even about direct, financial incentives. It's a win-win for both ISP and content providers to peer directly and limit the amount of traffic routed through paid uplinks. It's a win for users too, since they can get their content with less hops, through bigger pipes. Even Tier-1 network operators (https://en.wikipedia.org/wiki/Tier_1_network) can optimize traffic by making the direct inter-connections for traffic-heavy content.

When everything is encrypted and goes over the ISP just to the VPN endpoints, they can't do anything. In the end, they will have to arrange peering not with content providers but with VPN providers, who works for Apple.

PS. There is a lot of tension in current setup, even without Apple stepping up. In the old fashion market, the last mile is the king. Big grocery chains have direct access to users, so they are the strong side in the relation with producers. They can position brand X over Y, if they have better margin. They also create their own brand Z rip-off and sell that directly. Just look what Amazon does in that space. When it comes to ISP, they have direct users and have very little to say. They are basically dump pipes, just like the power line.

T-Mobile was very vocal in the past in that space. They often wanted the MANGAs (heh) of the world to pay them a share from their ads. I remember T-Mobile threatening, that they might replace some ads with their own ads. Since they provide the users with phones, they can install their own certs on devices. Chrome has SSL pinning not only, to save users from hackers, but to save their own business model being attacked by ISPs.