> Looking at graphs with clear improvements on many metrics .. one of the UK's most hated things the government has ever done
This is a classic of metrics driven management, isn't it. Customer satisfaction isn't in the metrics so people stand around saying "well they should be happy!"
Mainly about the cost, but the overcrowding on certain lines and the unreliability are also major factors. Commuters end up using the train because they're more or less forced to - you're not going to drive into rush hour London, and there's nowhere to park; and that's also a matter of policy to get people on the trains for sustainability reasons.
The "playing at shops" market setup exacerbates the problems. Original comment says "costs have gone down due to competition", but since the UK's operators are little regional monopolies they don't actually compete. The operators own neither track nor rolling stock; most of the money flows to the "train landlords", the ROSCOs.
Privatising the track, through "Railtrack" was the big disaster. They cut maintenance, but when you enshittify railways eventually people get killed, and nationalization was inevitable after Hatfield.