America has much more serious problems with rail, but the UK experience still isn't great. The broad root cause is that back in the day we had the genius idea of paying multiple private companies to run trains on shared lines. We set up metrics to measure their performance that, bluntly, do not work. They underinvest and when there's any sign they're not making money, they hand the contract back. All in all, we get all the disadvantages of a nationalised system with all the disadvantages of a privatised system with a couple of original problems thrown in for good measure.
>The broad root cause is that back in the day we had the genius idea of paying multiple private companies to run trains on shared lines.
Train travel has doubled since the privatisation.
The main problem is we don't know how to build out infrastructure in a cost effective manner (see HS2 and the electrification of the Great Western Main Line). This isn't surprising as we do it in a stop/start manner rather than a continual process.
The infrastructure privatisation was reversed a long time ago, and most of the delays, in my experience, are due to problems with tracks.
The biggest problems recently (for me) have been strikes and inadequate services. The rot really goes back to pre-privatisation (it was not great in the 1990s) and arguably started with the Beeching cuts of the 1960s, based on the decision not to subsidise rail in the face of increasing road use.
But the train near my house still runs.