I agree with your first part, it is hard to save money on the dining plan now if paying cash, as you say you need a lot of expensive meals to make it worthwhile.
But looking at the offers to the UK the free dining offer for us was a significant saving. I estimated for two of us, over a 14 night trip we would spend £1000 on food. There is no other offer that saves that sort of amount. This year they are offering up to 4 free nights for 2021, that is almost a similar saving, but last trip I paid about £200 a night so the free dining was the bigger saving.