The one is a dish or preparation method, the other is a food group.
A vegan sausage or patty is foremost a preparation method . nothing in it intrinsically requires it to consist of meat.
It’s only deluded Vegetarians - a subset of vegetarians, mind you - that try to claim that, say, a vegetarian pattie and a meat patty are the same and thus exchangeable. Except of course, that the vegetarian one are better for you, God, the environment, your health, the animals, and so on.
And there a probably bad Vegetarian restaurants around. I certainly met quite a few cooks who had trouble serving Vegetarian meals, because all they can do is leaving out the meat in a dish, which quite often isn’t enough. But since there are plenty of bad cooks and restaurants serving meat badly, bad cuisine isn’t an intrinsic feature of vegetarian cuisine.
