I wonder if the "Rail" figure includes London Underground, it would make a significant difference.
There will be very many other detailed and nonsensical situations across the nation that cry out for early attention if punctuality and comfort are to be improved.
Regarding train size, and noting you write from Sheffield, I was there recently. At 3pm in the afternoon there were plenty of passengers waiting at Meadowhall to go into Sheffield, in came the train - a single car 153, already full. Stood into Sheffield, where as we all alighted there was what seemed a well-rehearsed jostling starting on the platform of returning college students, and others, for its next working, which I think was to Lincoln. I would guess about 150 passengers. It was worse than morning peak northbound on the Victoria Line at Victoria. I stood and watched, they didn't all get in, 10 minutes before departure.
Now I'm long in the tooth enough to remember Sheffield a generation ago. There seemed less passengers about in those days but the local services I used on these lines were mainly 4-car coupled Class 114 dmus. Quite how train provision has been allowed to be one QUARTER of what it was then, yet patronage (and ticket revenue) has gone way up, defies all logic.
I used to travel from Taunton to York, when it was an 11-coach express you always got a seat. Nowadays it's a 4-car Voyager which can come into Taunton already with standing passengers. Enough of that, guess what, especially when with others in the family, we now drive.
As an example people justify a large car for occasional trips, yet mostly just use it for short trips to and from school which could easily be walked.
That's because families have just one car.
In passing, the general public (including me) get a little hacked at this constant reference (TfL especially) that we can "easily" walk or cycle some journey. If it was easy we would do it. Our school (nowadays inner London) is 9 minutes away by car. Walking? Probably 1.5 hours. And do we have to walk home the same afterwards, and walk it again in the afternoon to collect them? Have those suggesting this ever walked such distances with young children?