Ive never heard it's not possible. Whether they want to offer it (ie, put in the $ to provide it) is another completely different question. With domestic F fares where they are now compared to where they were when they did that kind of stuff, not to mention upgrades these days, so every seat full, not really surprising the offerings are cut back. We get what we paid for. Americans speak with their wallets. And while there are absolutely some who are willing to shell out extra $ for these kinds of amenities, in general, Americans have shown, time and time again, that they are not. The history of domestic air travel is rife with examples of it. Demand the low prices, then complain about everything that it doesn't come with later.

It's been a long time, but AC used to serve a 'snack' plate - not a hot meal, sure, but a pretty decent snack plate - on Rapidair flights YYZ-YOW/YUL - something like a sandwich, bag of chips and dessert. To everyone in Y. AI did, and I suspect still does, but it's been a while since I've flown this kind of flight, serve a full hot meal on short domestic flights that were 1 hour or so. Even more, TG used to run wide bodies on many domestic routes, with a full meal to everyone in Y - personally, flew BKK-CNX in Y on a 747 and received a full meal along with everyone in Y.

Is it possible - absolutely? Whether domestic US flights earn the revenue, or have the work rules that allow the FAs to do the kind of work needed for this on shorter flights anymore - that I doubt. For the record, I stopped expecting anything more than minimal on short-haul in F a long time ago. I also find it interesting the amount of people that lament the lack of food, but also complain about what they get on the flights that do have it.