the "meat" in "meatless meat" describes a texture and taste profile, not an ingredient. It is easier to communicate than, say, "chewy but soft, fibrous proteins which taste is usually determined by umami and maillard reaction flavors".

There is a large community around new recipes for this taste profile, e.g. https://seitansociety.com/ .

compared to the logistics (animal farming and slaughter pipelines), artificial inseminations, medical interventions (antibiotics), storage and food safety concerns around meat, plus the incredible daily amount of animal suffering caused by this consumption, I don't see meat as a "natural" product. all the steps in the "production" process can introduce factors that can degrade the quality and be risky to health (e.g. not cooled at appropriate temperature, antibiotics treatments to animals etc), while with plant proteins, you have far less processing steps between field and table. to vegans and people concerned with reducing global warming, the benefits outweigh the different composition by far.