That doesn’t say anything though since there are so few vegans to begin with. Protein is also trivial to supplement.

Not hard to google that. There's even a website: https://www.greatveganathletes.com/

I think that's a silly argument anyway, if we're discussing health. Professionals do plenty of stuff that is awful for them to get performance gains. Steroids, exercise routines that are very punishing on the body long-term (plenty of power lifters who can barely even walk after retirement and they aren't that old), etc.. I am not sure you can say it's good for you if professionals do it... maybe good for short term performance, but not "good for you."

It's actually easier to get protein if you like legumes (including tofu and peas, not sure if these are technical legumes), gluten, and/or nuts. All of these have amazing nutrients, are really cheap, and easy to digest for most people. If they aren't for you that's ok - some people can't digest meat either.

Not saying you don't need to take some supplements as a vegan. You probably do, at least b12 and maybe omegas, but you're getting those from "supplements" anyway from meat (it is just fed to the animals first).

I think one exception is that some fish seem to promote health in moderation. I personally don’t find it worth supporting the fishing industry or killing countless animals to get the fish I want, so I’m content without that in my diet. And like you mentioned, supplementing omega is an option (even if it isn’t as effective with vegan options — I’m not sure).

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.