I don't know why people say it's difficult. You just stick the meat in the over, and spuds if you want roast potatoes, and steam the veg. There's some prep to the veg, but so there would be if i was doing any other meal with veg. And the gravy needs doing at the end, but that's not difficult either.
We used to have a roast on Sunday, then carry on Monday (or sweet & sour, if we'd had pork) and possibly more leftovers in sandwiches or an evening meal on Wednesday. Chicken carcass would also get boiled up for stock. Veg often came from the garden, and it was a great treat to have the first carrots, the first peas, the first asparagus - and we definitely didn't have roast spuds when it was the first new potatoes of the season.
Having said all that, I had a roast on Sunday in a pub, because I hadn't had one for ages and fancied one, and it was a huge place. I hadn't eaten much in the day, so I managed, but it was 3 huge slices of beef (it was good beef,) 3 o'r 4 roast potatoes, a large Yorkshire pudding, carrots, peas, broccoli, cabbage, creamed parsnip and a breaded parsnip, plus gravy and horseradish - it would have been a fine meal with about half all that. (Mind you, I don't know if that's what you usually get - they were about to close the kitchen when I ordered, so they might have been using up the last of the veg etc.)