The protein problem is a myth. And what percentage of the population is involved in athleticism that requires significant amounts of protein? This scenario is so uncommon as to be irrelevant to the average person.

I run, dive, lift weights, and rock climb without any issues. If I did it competitively I could easily supplement with plant proteins. Virtually anyone I know who eats meat and trains hard has also supplemented with whey or something similar. There doesn’t appear to be a meaningful difference when eating plants.