What is your opinion of this way of eating?

I am considering participating in a permanent lifestyle that will change my diet forever. The diet has a few iterations, but the branch I will be following most closely is Dr. Esselstyn’s diet.

This diet is called Whole Food Plant Based No Oil, low fat. It is essentially a vegan macro diet, but it is rather specific. Forks over knives a wildly popular documentary promotes this lifestyle.

On it, one eats only plant based foods, with a diet high in complex carbohydrates and starches. There is no room for extracted oils of any sort. No room for animal products, at all. B12 supplementation is advised. Beans and legumes are limited slightly. There is no other limitation to speak of besides the avoidance of caffeine, and coffee in any form.

Looking for honest expert answers, thanks.