You are correct about the existence of complete plant proteins. There are studies that show an advantage in lean muscle mass gains for groups that consume animal based proteins https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7926405/#!po=29.1667

I definitely believe it is possible to gain significant lean mass on a plant based diet, it just requires more effort than an omnivorous diet in my opinion. I would be open to seeing studies that challenge the one I have sourced but I am paywalled from the one you have linked.

My original comment was just a warning to combine your plant protein sources wisely to achieve the best results. I did not mean for that to get lost in translation.

I was specifically speaking in the context of muscle protein synthesis, not the bare minimum required to be healthy. The daily required amount is not enough to become “swole”, this can be seen in the daily value recommendation of 50g, anyone who lifts can tell you that is not enough. I am not claiming it to be impossible to be swole and vegan but you need to combine protein sources to get all amino acids required for muscle protein synthesis. There is a reason many popular vegan protein powders are a combination of sources (pea and rice normally). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6723444/

Plant proteins don’t have complete amino acid profiles, so it is important to research which vegan protein source contains what animo acids and combine sources accordingly.