The 321s and 317s had no amenities whatsoever. No air con, 3+2 seating, no charging points, absolutely nothing. And I think the FCC 313s might just be the nastiest train I ever set foot on.
Class 313s were bult in 1976, class 317s in 1982/86 and class 321s in 1990. Back then, passengers read newspapers magazines and books, or listened to cassettes on a Sony Walkman. Batteries were huge, and nothing was sufficiently portable to need to charge on a train. There was no internet, never mind wifi. But all of them moved large numbers of commuters in reasonable comfort, except when the weather was vey hot.
I actually found the lack of tables (big enough for a laptop) and armrests on the 365s quite irritating
When the class 365s were new in 1997, nobody took laptops on the train, as there was still no wifi. Laptops needed a dial up internet connection, so were not any use on a train.
In WAGN days catering facilities were provided on the Cambridge and Kings Lynn services on the Class 365.
That's because people stopped using the on train catering. That was partly due to faster journey times, after the 1999 timetable acceleration, but mainly passengers switching to the proliferation of on station refreshment outlets, who served a better quality product.
It just feels that GTR have turned the GN Mainline services in to a metro/commuter service.
The Kings Cross service hasn't been "main line" since electrification in 1978, and the Liverpool Street route hasn't been "main line" since through trains to Kings Lynn finished in 1990 prior to electrification north of Cambridge.
FCC turned the London-Cambridge/Fen Line into a commuter service because they had to, in order to cope with the huge increases in loadings, especially London commuting, when they first took on the franchise. Now GN has to deal also with the huge amount of inbound commuting traffic to Cambridge, especially from Ely.
Featuring metro style stock as in the Class 700s
The Cambridge stoppers are a Metro service and the class 700s are ideally suited to the task. Very few journeys are long: most Kings Cross/Finsbury Park passengers are not going beyond Knebworth, Potters Bar-Royston is the Hertfordshire Metro, with lots of short journeys and lots of people getting off and on, and north of Hitchin becomes a commuter service for Cambridge. Very few passengers are on the train for more than about 40 minutes.
And don't forget that the Cambridge stoppers are mostly class 700s because it was originally intended that the trains would run through the core to Maidstone. Be grateful that you never had to put up with that!