The answer depends on who you speak to.
In a society where almost (always have to add this qualification as there's always an exception

everyone wants a car and to use it as much as possible, the railways now simply act as an alternative.
Commuting and travel to airports must form the majority of journeys. Given people commute much longer disances than in the past, that encompasses much of the former Inter-City network.
Long distance travel within the UK has competition from the air although this appears a crime against nature. Trains appear to be built for speed rather than comfort unlike the old saying about well built ladies
Passenger numbers have increased dramatically but I'm not sure whether they want to use the railways or have little choice.
So the railways are for people who can't use a car. Given many lines have as many passengers as they can handle, that would appear a good enough reason to have them.
Enthusiasts view them as entertainment but they clearly don't have the place in the nation's psyche they used to have.
Very good at hauling bulk freight as well. Despite all the good intentions, the roads will always dominate for smaller loads.
Far more mail and parcels could use the railways.
I'd extended freight services to airports. No idea why no one's ever thought of this?
The railways require radical thinking with new lines, old lines reopened and others closed to make best use of resources.
One thing is for sure, you can't attempt to force people to travel by rail and hope for contented passengers.
It would be a good idea to ask the population as a whole what they see as railways being for. I suspect it's for someone else
PS
Don't take this too seriously.
Only a few thoughts posted in response to Slip while waiting for my dinner
