In the UK anyone who matters lives or at least works in London, which has always had decent transit and has been gradually, incrementally nudging cars out of the centre for about two decades now (congestion charge, ULEZ, gradual pedestrianization of very central parts) as well as improving the alternatives (crossrail, actually decent cycle routes). Part of it is probably simply that London never completely stopped building new transit for too long; as much as UK people complain about transit development happening in fits and starts, there's always been a sufficiently new and shiny line to point to as a success and an example of how transit should be (Victoria, JLE, DLR, crossrail). But I suspect it's mostly just not having your expectations set by a largely LA-based media.
It does apply to the UK. Very little new public transit gets built, what's there is permanently overloaded. Whenever I visit I regularly end up on trains where you have to stand for the entire 1hr journey. Many lines are full and can't be easily upgraded short of massive signalling reworks (moving block etc). Reliability is poor because there's no slack in the system. Root cause is more people + little/no new capacity.
It’s all relative, of course. I live in Dublin, a city not exactly known for its amazing public transport (we are currently on attempt number three to build a proper metro - we’re currently at the planning approval stage, so it’s probably doomed). At some point a colleague from San Francisco who’d been living here a while mentioned how good the public transport was (and this was a few years back; it was worse back then than now). I was quite confused, until I visited San Francisco.
And then on the other hand, every time I’m in Germany I’m amazed at how good the public transport is. But I’m fully aware that complaining about the trains is basically a national sport in Germany.
Like, you’re complaining about the trains being full, but at least the trains _exist_.
I didn't say it doesn't try, I said relatively little gets built. Crossrail is a great project, notable for its uniqueness, and the fact that so much is underground (the only place you can build nowadays, and even then just barely). HS2 has to go above ground and doesn't seem to really be happening.