I think you're citing pretty much a best case there. I just put in the same journey on a morning next week and got £150 each way, which I suspect is still not the worst case.
Before the pandemic, my wife used to pay about £5K/year for a London - Brighton season ticket (a distance of about 50 miles).
Possibly the most infuriating thing is that it's highly unpredictable what's cheap and what's expensive, and long journeys can often be several times the cost of flying. From a social-welfare/cost-of-carbon and oil-crisis perspective, this is nuts, especially when you compare what Germany is doing[1].
[1] https://e360.yale.edu/digest/germany-slashes-summer-train-fa...