> the majority of apps don’t pay apple a cent

Every app in Apple’s App Stores makes them a minimum of 99USD/year, the cost of an Apple Developer account.

That's a trivial amount to enable Apple to provide documentation and tooling support for developers. I doubt it comes anywhere close to paying for all the libraries and frameworks they develop and maintain.

But you can publish multiple apps with one account

Why do you think Apple still makes Macs? According to your argument it should be a net loss for them.

People often complain about the markup on Macs, so it seems reasonable to interpret that as a higher margin being used to compensate for the lack of ongoing revenue. Higher margins are the obvious (only?) alternative to ongoing commission revenue - that obviously puts Apple at a disadvantage compared to

* Google, who makes money by harvesting information from every android user; or

* Samsung, etc who don't pay the cost of developing a platform

* Steam, GoG, etc who literally only operate a store front, yet still take 30% cuts. They don't even have significant proportion of free games - and the games that they do have are frequently > $50 so their per-sale absolute revenue is insane.

* The various console platforms, because somehow consoles are magically different from everyone else

* Microsoft (ignoring consoles) who charges for their OS, and despite that seems hell bent on putting ads into the OS

Are margins on Macs higher than on iPhones? I’d assume at least with Intel they were lower than for iOS devices.

Also basically all Apple’s direct competitors both in the PC and smartphone businesses operate on paltry margins in comparison to Apple. They usually sell a mix of low/high margin products though, e.g. most premium Dell or Lenovo laptops are priced at similar levels to Macbooks (of course their real price might significantly lower due to infinitely better customizability and reparability options). And almost none of them have significant additional revenue streams (not to a degree comparable to Apple). Yet they are still in business.

Apple would be able not to only to survive but to still thrive if they significantly cut their margins and the app store tax. Of course it would not be fair or sensible to expect any company to leave free money on the table. This is why we get ads in Windows, seem like most users dont’t really mind them too much (to be fair I’m not sure I have actually seen one, maybe it’s a windows edition and/or country thing.