I agree with your point that it makes sense that he has the best audio. But regarding "in a profession": I believe he still has a day job; I wouldn't call being a youtuber his profession, being a youtuber is a hobby for him.
His day job is (was? I don't think he did anything illegal, but he may have violated employee codes, and well, he's a multimillionaire now) Financial Wellness educator for Mass Mutual, and in the pandemic Educator also requires good audio.
