the manufacturer of the gsm and cellular hardware do not what their products to be commodities that users can interchange easily. They want their commercial supplier contracts to be between negotiated cartels, which allows each producer to eat a certain horizontal slice of the pie.
Every player in this space currently has this incentive imho.
They always had.
While everyone that was doing vertical integration in the last century, had the whole product to sell, the OEMs selling IBM PC clones were all alike, so they always had something to differentiate, being the shovelware that was offered alongside the PC, pre-installed, painted cases, whatever.