They can, and on LNER I've had decent evening meals pre pandemic, but ATM are choosing not to provide it. And at less of a mark-up than Club Europe appears to be on a random search.
Yes I've had some nice meals on LNER and VTEC. I do think East Coast, once they'd settled down after ditching the restaurant and at-seat dining (they had some howlers in the early days, anyone remember the beetroot risotto?), offered a better product overall that those that came after and during VTECs tenure things definitely got more stingy but I've still had plenty of good meals. LNER seemed to actually be starting improve things pre-pandemic and getting closer towards what East Coast had been offering. But it's disappointing that they've taken this long to get back to serving the sorts of things they were pre-pandemic.
They are serving some good stuff (and the harmonisation over the weekend with having alcohol and hot food is an extremely welcome improvement that not even East Coast managed) but still no plates, the glasses are definitely pretty titchy (annoying for wine drinkers I'm sure) and we're not back at a full menu (no proper cooked breakfast, no evening meals, etc) so it is somewhat disappointing that we're still no further forward.
Of course I appreciate that for some nothing is ever good enough because they want booze by the bottle and breakfasts that wouldn't be out of place in the Olympic Village but for me just get back to what East Coast were doing in their pomp before VTEC arrived (and continue the enhanced weekend offer, which I think is the best on the network pre or post pandemic*) and I'd be a very happy camper.
*EMT of course offered full breakfast services on a weekend. But that was only on a handful of trains and only in the morning! Nice if you got it but LNER is better overall as it's on all services across the day.