I don't know the detail of the complaints, but EE along with many other broadband providers use the BT network, so actual line fault occurrences should be no different you'd have thought. Perhaps it's the handling of the complaints.
Ironic that BT owned one of the founder mobile network companies and split it off.
Integration of fixed, mobile, broadband and TV now seems to be the name of the game.
I'm surprised that Virgin don't suffer reliability problems with their network judging by the cable run to my daughters house.
The small access plate in the pavement has been smashed to allow the cable to exit and run on the surface of the pavement and then along the surface of the driveway and to the house wall. The street cabinets often have the doors swinging open.