That's a pretty big assumption.
Meanwhile hardware and network owners madly fight to stay relevant, like the aggressive customization of Samsung's android Touchwiz or the various telecoms lobbying against net neutrality.
The era of multi-year contracts and heavy device subsidies has primarily helped those with large market share maintain it. T-mobile in particular has been pushing to change how the market works and bring an end to some of the ways that customers have been locked in to carriers. I wouldn't be to surprised to seem them support further commoditization.