In my experience cooking (which I do a lot, for a large family), it's generally faster to produce a high umami meat-based meal than it is to create a vegetarian or vegan one. The main reason I find is that I have to cook vegetables for much longer (with sauces, etc.) to develop the rich flavors that are "built-in" to something like a steak (which I can cook in 10 minutes).
err no it doesn't.
> Realistically, vegan food prep takes a long time
err no it doesn't. If you are cooking actual food, then it takes no more time than cooking food that you are add meat to.