Are rail fares in the UK unfairly priced?

The cost of railways in Britain is shocking! There are some options to book in advance or through a third party to make the journey cheaper. There are also website which can calculate "split fares", where sometimes it is cheaper to get two or three separate tickets for a single journey which takes place on the same train - no need to get off the train, it's just a quirk of the ticketing system that three connecting journeys are cheaper than one long one. But this kind of thing should not be necessary. Many people find it cheaper to fly abroad from England than visit other places in the country, and I cannot see why running a train is cheaper than running an aeroplane. As well as this, you can pay a lot for a train ticket and not even have a reserved seat, so travel in the corridor, or standing up at busy times. Upgrading to first class, in order to have more space, is sometimes not much extra and is a tempting option sometimes in order to have a pleasant journey, but you pay so much for the ticket you'd hope to have a pleasant journey anyway!