You can make seitan from scratch. I start with vital wheat gluten (and chickpea flour and nutritional yeast), which is technically a processed product. But you could start with flour if you wanted to.
The end result is a product with 3 or 4 simple ingredients, compared to that fairly large list of unknowns.
I think this is missing the point. Yes you can make seitan from scratch, but it's not necessarily going to be better since seitan with its main ingredient being gluten contains little fiber either way. On the other hand, chickpea flour may be processed, but if the process preserves the fiber, that's not really a problem.
The lack of fiber in /most/ processed foods makes you eat more of these.
The end result is a product with 3 or 4 simple ingredients, compared to that fairly large list of unknowns.