True. If you book at short notice Newcastle to London after a Newcastle United fixture, you will find there would certainly be no reservations to Durham/Darlington, so you'd need an Anytime ticket.The second and more-difficult-to-address problem is that you just won't be able to get these tickets if all the seats in the train are booked, even if you're willing to stand. I'm not always able to make plans with multiple days of notice, and if I have to get the train at short notice then even standing for 4 hours would be preferable to not getting home at all, only now it will be literally unaffordable. I'm aware that Virgin EC and subsequently LNER have had a bee in their bonnet about people standing ever since Corbyn did that attempted hatchet-job, but having been in a shouting match is really not sufficient reason to effectively break the relationship the railway has with a large proportion of its users.
LNER would of course want you to pay nearly £200 but the forum's site would only sell the Anytime fare for the part of the journey for which there were no Advances. They'd probably be available from York, if not Darlo.
True but LNER know that at busy times, even if many people do go by car, there will still be many people prepared to pay £hundreds to travel by train for the "freedom" to be able to watch Youtube etcPeople accept awkward fare structures for flying because it's so fast. But the car competes with most rail journeys, and as such you need to offer that flexibility else a lot of people will just drive. A new EV is looking very attractive at the moment.

If Newcastle are at home to Arsenal, Spurs, Chelsea etc then they want people to be paying £195ish rather than £85ish, and if a few hundred people drive down the A1 then they'd consider that job done. Even if they get half the customers, they are still quids in!