"There are highly processed food ingredients like whey protein and resistant corn starch, oat fiber, etc which have compelling health-promoting effects."
Cod liver oil comes to mind ...
I would seriously doubt claims of health benefits of the incomprehensible ingredients on the ingredient list. Those things are there because of the constraints of "manufacturing" food that is appealing, stores well, ships well, etc. It's not about what's good for you---it's about what isn't acutely toxic and maximizes the company's profits.
The problem is that people are ignorant with regards to the purpose and effects of various food additives/ingredients, so they just take the simplified stance "more ingredients = bad" rather than do a little research. As a heuristic it might be fairly functional (you can still eat unhealthily without processed foods though), but it means you're going to spend a lot of time preparing food and you're missing out on the opportunity for engineered superfoods.