I don't think everyone needs therapy. So that premise is false in my view. I mean, the argument is something like, "society is messed up so everyone needs therapy. But if society is messed up, then we should focus on fixing society instead of individuals."
However, I believe it's much more complicated than that. People can also "want" therapy. They don't have to "need" it to go.
I'm at a point where I both "need" and "want" therapy because it's geniunely helpful for me.
Also societal wrongs do not necessarily "cause" mental illness (once again, in my view).
I will admit, however, that there is individualism present in the whole statement that people should work on themselves. Maybe we should work on the "collective" instead or in conjunction with "working on ourselves."