Highly unlikely. Pipex, whom I've been with since 1966 on a dialup connection, is one of the oldest and most renowned ISPs in the UK.
It originally largely catered for big businnesses before enlarging its domestic base and BT would play a big role in that development.
As you have already discovered, Pipex support is first class and, in my sole experience of needing to contact it over the past nine years, fully merits your approval.
My son, when he first took up broadband about three years ago, switched from a Tiscali dialup account to Pipex and has never regretted it.
He acknowledges that he has had to pay a slightly higher fee annually for his Pipex broadband service, but woudl quickly point out that the promised speeds, upgrades, personal website maintenance and overall support has been of the highest order.
I'm aware of his views because, as you may perhaps be aware from other threads, I'm finding Tiscali's broadband provision something of a pain in the.......:-))