The UK could have had world leading broadband were it not for Mrs T. She decided BT's late 1980s decision to rollout fibre was anti-competitive and killed it in 1990 when we were pretty much leading the world [0].
So the grindingly slow reality of ADSL isn't especially surprising sadly.
[0] https://www.techradar.com/news/world-of-tech/how-the-uk-lost...