> 2-3x as expensive

That seems a small difference in contrast with the industries scales and the price comparaison will probably be the opposite in case of expended demand. Also most plant diet are already cheaper and that little supplement wouldn't make a difference.

> PSMF for bodybuilding

You may have not found a plant alternative for your needs but it seems you are on a quite unusual diet. "do not provide significant protein or fats" apply essentially to the group of people that are bodybuilding AND on a similar nutrient diet AND eating "whole sources" only. For anyone else, it's fine:

- sedentary: most plant protein will do fine, they are packed with fibers that helps transit the carbs/fat and regulate insulin

- sedentary with cardio/active life (commuting by foot/bike, running, swimming...): same as sedentary, as you noted you got all the carbs needed with the meal.

- bodybuilding not on a "whole sources" diet (milk, whey, chicken without skin...): Plant shakers are similar to their animal alternative, and protein isolate can be prepared of cooked the way one want.

You seems quite informed so it may not be that hard for someone as much informed as you, but I concede plant diets are not the norm and most people just don't know how because they learned to eat differently instead. As an athlete you probably know that it seems hard to change habits.

Regarding the price we don't share the same experience: proteins are cheaper, restaurants meals are cheaper and societal cost (subsidies) is cheaper. Some specific supplements may be more expensive but that's marginal.