quickymart: I wonder about that too, but then again they have invested a lot of money into it, just to walk away from it all and start paying someone else to use their network, instead of their own.
I think the long term play is 5G, fixed wireless and fibre for businesses and consumers who are heavy users. As others have noted, at some point you have to cut your losses or otherwise you'll get stuck in the sunken cost fallacy of throwing more money because "it would be waste if we cut our losses when we've invested so much". I could imagine in areas where it is possible to have line of sight to the tower that mmwave might be a possibility as well.