[graemep]

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.