Fancy gourmet cooking is very expensive. Only a limited number of people can afford it. Also, this kind of cooking is very rich and if you tried to eat it every day, you would soon become sick and eventually die of something like heart disease. But anyone can go to the store and buy basic food. It is also much better for you to eat plain, nourishing food.
Simple meals are better for the health.
Shakyamuni's luxurious appearance was necessary because the people of his time needed to see that kind of figure in order to believe his teachings. They needed a luxurious figure of a Buddha rather than the original form. From that lime on, they practiced Shakyamuni's Buddhism little by little. Nor was it because they had committed any of the eight rebellious acts. It was because they met someone who was an evil influence, and discarded the Lotus Sutra to take faith in the provisional teachings.