It is worth remembering that VMO2 *are* a Openreach reseller though.
O2 are a large-ish player in the business broadband/ethernet/wifi game.
https://www.o2.co.uk/business/soluti...d-and-internet
https://www.o2.co.uk/business/soluti...ity/o2-gateway
A lot of the public wifi networks are O2 networks. There is just no consumer side to the FTTC/ADSL business - yet.