Interesting, also UK here, never really noticed problems with our toilets on the scale you are describing. There are some that annoy me because you need to push the flush a couple times (pump action), but fairly rare.

Whereas with US toilets, I just don’t get them. The low flat bowl is weird, discourages peeing standing up, and then the design of most public and business toilets with those massive gaps on the doors, giving you no privacy... what’s with that?