I too remember British Rail before privatisation and didn't think it was that bad. I commuted from Essex to London in the mid sixties and then from Suffolk to London in the mid eighties.
The trains to Norwich were comfortable two seats with a table on either side of the gangway. More suburban trains at 5 sides across the width I think.
There were delays but not all BR's fault. They would range from suicides, children playing near the line, youths throwing rocks and blocks from bridges, vehicles entering level crossings after the warning bells and also leaves and the wrong snow.
A delay to the suburban trains could affect the other trains using the same lines because there weren't enough passing places. I remember one time I was reading and savouring my G & T and thinking that we ought to be coming into Ipswich. I looked out of the window to see that we were over the M25 - it had taken an hour to get that far.
Some of the offshoots, such as catering, British Transport Hotels, Sealink and engineering. All of these went during Thaatcher's "reign"
Before privatisation we used to be able to go up to London (after I stopped commuting) for an evening out for £12 return, using the nearly empty trains going to collect the commuters.
After privatisation we had to specify which train we would go on. Not wanting to leave a performance before it finished, we would book the 11.30pm from Liverpool Street. One day we were in time for the previous train and so got in it. The jobsworth told us that we had to get off at the first stop - Colchester and he watched to ensure that we did so. it made no difference to him because there were plenty of seats bu "I'm just doing my job"
In Europe, on long distance trains, all the seats are reserved because you have to book in advance. Once, coming back from Rome by train (caused by Ryanair cancellations) we got the last two seats. Had there been no seats we would not have been allowed to get on that train.
I am a bit of a train nerd. One day I went home from work via Euston because the Mallard was coming to London. The most beautiful train you ever saw, or will see probably.