Interactive version: https://back-on-track.eu/night-train-map/
night trains are for long distances. Can’t really do that on an island. Night trains are basically just sleeper trains, but those connections need more than 3-4 hours of distance to make sense
… yes, I know what a night train is. Your point?
For the record, there are far longer routes in Ireland, Spain and Portugal and far shorter routes captured in the map (in distance, we could have a long talk about the pros and cons of promoting overnight train over high speed rail for the same trip).