I think it depends on where you are going. My local commuter link into London is OK and reliable, if expensive.

Long range trains from, say, London to Manchester are often overcrowded and ridiculously priced.

I take those long distance trains and it amazes me the choice and how low the cost is. You can choose an empty high speed service in peak time with a 20 minute frequency for a high cost (comparable to flying), you can book ahead for a lower price - especially in non peak services, or you can choose a flexible lower speed (comparable with service in the BR days, 3.5 hours) for far cheaper than it ever was.

Season ticket prices are under 20p/mile into London

Nationalisation will likely break this and increase costs for all but the richest. For the last decade the public have been clamouring for “simplification” because they couldn’t understand the restriction codes. Now it’s being rolled out they are of course seeing price rises and complaining “not like that!”