Good news for vegan body builders. As more sophisticated studies start to be run, it seems like plant protein is probably basically as good as animal protein for muscle building - as long as you eat enough of it of enough varieties.
On a gram-for-gram basis, animal protein is certainly of a higher quality than plant-based protein… But if you’re consuming enough of plant-based protein and in the context of a whole meal, those differences really don’t come out in the wash.