In the UK, the physical telecoms network is managed by Openreach, a wholly owned subsidiary of BT Group plc. Basically, if you don't have cable internet access (which is in turn owned by Virgin Media) you'll have to use the Openreach network. It doesn't matter who your internet service provider is. You also can't contact Openreach directly, so if you have any internet issues you have to play Chinese Whispers (also called the Telephone Game) to get anything done. It's not strange to wait months for your internet access to be restored if it goes down due to a physical fault.
The telecoms regulator, Ofcom, has attempted to separate Openreach from BT in order to provide equal access to the network and hopefully improve service, but BT itself still owns all the network infrastructure, and they're still owned by the same parent company, BT Group plc.
I've had horrible experiences in the past trying to get internet installed to my house, to the extent that I even called my local Welsh Assembly minister to try and get things sorted. It went all the way to the Minister for Skills and Technology, but at the end of the day it was still months before anything happened.
Compare this with Welsh Water, the non-profit tasked with providing drinking water and wastewater services to most of Wales. I discovered a damaged manhole cover in my backyard, and went to their website to see whose responsibility it is to fix it. I found a live chat option, and they quickly arranged to have engineers visit the same day to check it out. This was followed up by a phone call to arrange a suitable time.
Please, tell me again how profits (more than £1 billion operating income in the case of Openreach) are necessary to provide good customer service and a working system.