I think the issue with rail travel is the hassle and price of it.
Firstly, the luggage space, especially on virgin trains and in the case of the North, TP Express , is abysmal. There have been a few times I’ve traveled on Virgin with a large-ish case, and often there has been a struggle storing the bag unless you are one of the first on the train.
Then there is the price. When train tickets are often higher priced than the flight the person has just taken, no wonder it puts people off. I couldn’t count The amount of times I look at twitter and see people posting ‘my flight from Berlin was £20 but my train home was £45’. Price wise, correct me if I’m wrong, but isn’t the Heathrow Express is one of most expensive cost per mile rail journeys in the U.K. on a standard fare? Says it all.
With issues like that, if you are 2 or more people, no wonder people choose cars and taxis over rail travel. I certainly wouldn’t even contemplate rail travel for my family holiday, not a chance I’m lugging 3-4 cases, 2 hand luggage, 2 small children and possibly a pushchair on a train to get to an airport, with a change en-route too for me, I literally couldn’t think of anything worse.
Then long haul pax, do you really want to be waiting for trains etc when your shattered from a flight with again, likely large cases for such a trip?
Obviously rail is fine if you are travelling hand luggage only on a short break, but outside that, I really do struggle to see the appeal.