It is too one-sided to consider only the level of nutrition and health, and the influence of all levels should be considered.
The advantages of omnivorous food are: balanced nutrition, convenient eating out, and diverse tastes and foods.
The advantages of vegetarianism are: reducing the pain of animals, promoting physical and mental health, reducing environmental pollution and saving resources.
But the two advantages of reducing environmental pollution and saving resources are mainly aimed at modern factory farming. However, as long as you put yourself in the shoes with animals, you will find that even if you only consider the pain of animals, the advantages of vegetarianism outweigh the disadvantages.
Moreover, in the future, with the popularization of nutritionally fortified vegan foods, artificial vegetables and meat, the disadvantages of vegetarianism will be greatly improved. Plant artificial meat, artificial eggs and artificial milk have been developed abroad.