[swisstrains]

I keep reading about the Class 442 Wessex Electrics being withdrawn from service and put into store.
Coming from "up North" I have never travelled on one, in fact I don't think I have ever seen one (other than in photos) but they appear to be quite presentable and the railway press appears to speak highly of them.
Can someone explain to me why these units are being taken out of service when we are constantly hearing tales of overcrowding and train shortages on our railways.
TIA.