A lot of vegetables have enzymes that are neutralized by cooking (and yes, you can have them crunchy) such as broccoli which can slow down your thyroid if you eat a lot of raw broccoli.
Traditionally the cultures associated w/ these foods eat them in a cooked state or we have a long culinary history of these foods being cooked.
In other words, cook the veggies that are traditionally consumed in a cooked state and only eat the veggies in a raw state that are traditionally eaten raw such as lettuce or avocado.
And of course, there are foods that have been eaten in either a raw and cooked state.
And there is the issue of missing other important nutrients, vitamins, minerals, proteins, healthy fats when you limit yourself to one food.