I understand some of your replies about not even wanting to eat a vegan burger. It's a cultural thing, depending on which part of the country you're from. I lived for 30 years in, "ranch" country, where there were nothing but cattle and horse ranches, not to mention, plenty of steak houses, so I get it. But times have changed and I've moved on, gotten older and my nutritional needs are different now.
Personally, I really like the new wave of vegan burgers that have come out lately. Honestly, I don't think that anyone could tell the difference, once all of the fixins are on the bun with it. So now, I can enjoy my burgers guilt free and even have the will power to pass by an In-N-Out without having to stop. (Californians, you know what I"m talking about...LOL.)
In answer to the question of what the commercial burgers are made of...every company has their own recipe. Some use a soy base, others use wheat gluten base, usually there are some beans, or other legumes in there, along with mushrooms and other mixed vegetables. There's also the quinoa burgers, but they have a whole different texture. There are also lots and lots of homemade recipes like the lentil burgers mentioned above. You just have to read the labels and try them out.
Vegan sausages are on a similar topic...again Field Roast's Italian sausage and their frankfurters are probably my favorites, but the new Beyond Meat Brats are also amazing.
~ C