I'm not going to say he has no point, but 1: He's mostly just mad that he has to pay a cut to Apple and Google, 2: These companies spend tons of money curating, maintaining the OS/storefront, dealing with CC fees, gift card fees, etc and he conveniently forgets about all that, and 3: When you create a platform it's 100% normal for everything to have to go through your ecosystem (consoles, phones, etc) so he shouldn't pick and choose who he complains about.
He loves to pick and choose his complaints, such as Steam's 30%, while conveniently forgetting to mention that his storefront sucks, is missing tons of basic and more advanced features other storefronts (especially Steam) have, lacks multiple payment methods Steam offers (because it costs too much), and has a history of paying companies not to release elsewhere just to entice people to use it. Doesn't sound like someone who champions competition.