To me, the best way to create a regular menu that works for most is to have the base item and then charge extra for each protein - chicken, lobster, tofu, etc. It wouldn't work for every dish, but especially for pasta and salads it is nice to have a choice and to pay for exactly what I receive. However, after 25+ years I have given up on getting upset about paying more for less food.
My hunch is that chefs have a hard time because although they can create a delicious recipe without meat, for example, they are not as adept at creating nutritious well-rounded meals. Yes, you can cut up vegetables into tiny bits with sauces and pearls of things and it looks beautiful and tastes great, but it is not completely sustainable as a diet nor desirable for someone to eat regularly over multiple days.
Certain regions are better at certain dietary restrictions, in addition to the talents of individual chefs or F&B programs.