I think your perceptions of the 60s and 70s probably depended a lot on where you travelled. My recollections of the Southern inner suburban area was of a very reliable service, albeit with somewhat ageing stock (you could sink quite far down in some of the cushions) and floors covered in cigarette butts, discarded newspapers and other rubbish. They weren't swept during the day, so the morning's rubbish was still there in the evening. I think that sweeping of trains after the morning peak was a NSE innovation?
But the important thing was that even if something happened and the timetable collapsed, they would still keep trains running. So if something derailed, for example, it would be hoiked clear so that trains could run again asap, and recovered overnight.
Whereas the Cambrian on a Saturday, you never knew when you might get a train. You would turn up at the advertised time, and could wait two or even three hours. No staff to ask, no platform displays, no help point, no internet, no mobile phone to call anyone. If you left the station to find a phone box, you risked missing the train, so you all just waited. Even if a train came the other way, and you asked the guard, they were usually as much in the dark as you.
The North Wales coast line was much better. Except summer Saturdays, which could be quite chaotic. But at least there were station staff to ask, and who generally knew what to do. And even on the Conwy Valley, I don't recall ever being seriously delayed.
The Midland Mainline however was a different kettle of fish. It seemed to be the forgotten mainline. The loco hauled stock was old and dirty, the service slow and unreliable. Often I would turn up at Derby and there would be no clue when the next train to London might actually turn up, or when I might get to London. I used to dread my trips to Derby. That line was totally transformed when the HSTs were introduced.
One thing that I think we tend to take for granted these days is that most services now run on a regular repeating pattern. Back then, outside the suburban areas, service patterns were totally irregular, and often different from one day to the next. Timetables used to be littered with WO, TThO and the like. You really did need to refer to the timetables for most journeys. Nowadays, even on a line like the Cambrian, the services are two hourly, give or take a couple of minutes. Back then, if you missed a train, you would have to look at the timetable.
The most unhelpful timetable note that I still recall was Crossville's bus services that ran something like Tuesdays only, except Wednesdays on Llanrwst market and fair days. Of course, the timetable didn't tell you which were market and fair days, you were expected to know that. As I recall, markets were held in the first week of the month, except in months when there was a fair. And if the Tuesday was the last of one month, and the Wednesday the first of the next..... I got stranded once because I got it wrong.
My latter 1980s self did two All Line Rail Rover weeks, yet I failed to use that sleeper route; instead opting to go via London....
