Bottom line is that we could all exist on plant-based sources of protein - soy, seitan, Quorn etc if we had to and some cultures have done this successfully for thousands of years.
However, some people just do not want this decision forced upon them and are reluctant to experiment or modify their eating patterns
Sorry, i think thst is an oversimplifcation. If I go to my local fast food emporium and order a standard beefburger, I get all the proteins, amino acids, B vitamins, and some important minerals that my body needs and wants. If I go to same emporiium and grab a plant based variant, then I lose many of those nutrients. It does not matter if it is Quorn, Pea or Soya based, these are not 'complete' foods. I will have to add supplemental products to ensure I have the right mix.
I do not know what is in an Impossible burger. I cannot tell which of the elements are missing, that I will have to source from somewhere else. Similarly I do not know which plant based foods I need to eat to supply what is missing. But my single beefburger solves all that for me.
For example, I need to think also about Vitamins A, D3, K2 Omega-3, DHA and EPA. calcium, haeme iron, choline, taurine, iodine, sodium and potassium. These all come with the beefburger inclusive. A vegan burger is not a substitute for a standard burger - I don't care what it tastes like or smells like, or if it bleeds like - it is nutritionally deficient, compared to what I am accustomed to eating today. As I have pointed out the added heme iron in a single Impossible Burger pattie is twice the daily total recommended for a male. This means I can overdose on iron intake.