The contract that BT signed with the government for all the funding granting it a duopoly with Virgin, where Virgin isn't going to increase the cable network at all. That combined with the wayleave issues at a local council level being waved just for them means that the preferred rollout partner in BT gets all the money, all the profits from it and has all the access.

About the only nationwide competition that is even remotely happening is from Hyperoptic and they are being blocked all over the place and they are also really laser focussed only on high-density buildings.