BT is broken up into several independent companies. The business of physically laying last-mile copper and fibre and connecting customers is done by Openreach, who are required by OFCOM (the telecoms regulator) to provide fair and non-discriminatory access to their services to any communications company.
The same applies to BT Wholesale, who maintain the network and provide access to that network to communications companies. BT Retail are the company who send you glossy leaflets, but they have to compete under exactly the same terms as any other company - they pay the same prices to Openreach and BT Wholesale as Plusnet, Sky, TalkTalk or anyone else.
In addition, there's a completely independent fibre network operated by Virgin Media that covers the majority of households, and national coverage for HSPA from five different mobile operators. Brits love to complain about broadband, but I think we've got it pretty good.
And as a BT.A shareholder and ex employee I must admit to enjoying the fact that buzby is kicking that nice Mr Murdoch in the nads in football
And even if I did, that still doesn't involve BT.
I don't have a BT phone cable at my house though, so would need to pay for that to be installed if I wanted to go down that route.
I just object to not being allowed to use the hardware already installed with a provider entirely of my own choice, which would be the most efficient way to run infrastructure businesses.
There's also the cable option, but if you go down that route then you're actually more tied in to a single provider for services than with PSTN/ADSL.
My current house had BT at some point (there's a BT access box in a cupboard, but it's not connected to anything), but it was gone before I moved in - I'm guessing either as a result of some roadworks having cut through the wires or possibly a BT upgrade of their infrastructure, but as the people who lived there before me were on what was Diamond Cable at the time, BT clearly didn't bother doing whatever was involved in rewiring the house back in.
My only real complaint about them is trying to work out how to actually get the £50 Sainsbury voucher they promised when I signed up. Fortunately this seems to be the only part of the process that suffers from the old-style BT Kafkaesque processes....
Ironically abroad BT is often seen as the fast new innovative disrupting company when compared to incumbent telcos.