Hinderance, mainly. I live in the Isle of Man (not really UK, but certainly UK adjacent) and on a recent trip to Morecambe on the ferry with our bikes, it was notable how much better the cycling infrastructure - and there wasn't really that much of it - was in one the most deprived parts of England compared to the much more wealthy Isle of Man. The route into Lancaster along the route of the former railway line was fantastic, hard surfaced, free of debris, had street lighting - whereas our old railway routes you need a gravel bike.
The facilities we have are just not joined up. For instance, to go from my old work into Douglas, you can take some quieter routes and some cycle paths, and even the brand new cycle path that was physically built to LTN-1/20 standards, but then dumps you out at a busy junction leaving you with the option of (a) illegally riding on the pavement, or (b) making a dangerous crossing to the painted cycling gutter on the side of the road you really need to use. It's safer and faster just to ride in the road with the cars - they've actually achieved the dubious goal of making a LTN 1/20 cycle path more dangerous than just riding in the road.
The poor quality and un-networked cycle paths have in the most part made things worse here not better, because it has made motorists more aggressive ("Why aren't you using the cycle path"). Motorists seem convinced that massive amounts of money were spent on the ~3 mile "cycle path" along Gansey Bay, when in reality they just slapped some paint on the pavement and didn't even resurface it (while doing major work on the adjacent road, making it billiard table smooth). It's too narrow to be a shared use path - in most places a pedestrian and cyclist cannot pass without one riding/stepping aside into the long grass. The surface is also very rough, and there is frequently sections covered with fragments of broken glass from car crashes which neither the motorist responsible for the crash, their insurance company, nor the DoI see fit to clear up (they clear it up pretty quick off the main carriageway though). But whenever the police post a road safety message on social media that mentions cyclists, out come droves of motorists complaining about "how cyclists aren't using the cycle path on Gansey Bay after all that money was spent on it".
I've asked my local MHK (our equivalent of an MP) but the answer I got back from the DoI is that active travel has been defunded. Right now I would prefer if they removed all the useless cycle infrastructure, maybe it would stop motorists from doing "punishment passes" when we're not using the not-fit-for-purpose bike lanes.
They hope to expand our population by another 15,000 people. That's going to mean 10,000 more cars on the road undoubtedly trying to get in and out of Douglas every day unless they re-think transport.