Services not infrastructure
It seems to me that Ofcom and the CMA are backing the use of an extremely blunt instrument (ie the number of network infrastructures) as a tool for delivering suitable competition in mobile services. The mobile user in the street wouldn't recognise infrastructure if it fell on him, what he understands is services, and he doesn't give a monkey's about the number of networks.
Why can't these very clever economists understand that it's about competition between multiple service providers, not how many of them own a network? Do they also not understand economic efficiency? What is the cost to UK consumers in requiring multiple duplication of networks when, for technical and resilience purposes, two would do? It looks more like these high falutin' regulators cannot think up suitable mechanisms to regulate a services based market and are falling back on the old "make 'em build it" approach. Have we learned nothing in 30 years?
PS suggestion for new BT/EE/Or brand name: BTeehemoth