An alternative analogy: there are, sadly, far too many people who will go to a brick and mortar store, examine all the items in some category (laser printers, or jackets, or something), test them, try some of them on, decide which they like best, and then go home and order the item from Amazon. They’ve used the store as a free showroom. The store still has to pay rent, and keep the lights on, and employ staff, and stock all those items, but they didn’t get the sale. The person walks away thinking themselves to be smart (and the attribute “unethical” rarely crosses their mind). Of course the online price is cheaper, because the online warehouse doesn’t have to pay for a storefront (at high mall rates) and salespeople and such. The people mentioned above use the retail store, in the cruelest sense of the word “use”. (No, I’m of saying every person who walks into a retail store is doing this, only that some are.)
There is a similar situation with the App Store: Apple naturally wants to make some money off the App Store - it costs them money to run, and they are a business. And, except for the few odd huge cases like the Amazon’s and Netflix’s, they can’t do anything that requires substantial manual interaction / negotiation with each developer, because they’re dealing with a million developers. So, they set an across-the-board rate, and require no outside payment systems, to make sure they get paid. Why? Because if they said that outside payment systems were fine, 95% of apps would switch to “free in the store with an IAP through us to ‘buy’ the app”. Each developer would make some more money, and Apple would make almost nothing, but their expenses for running the App Store would stay just as high. Kinda like the retail stores in the previous paragraph. So, that’s why Apple is such a stickler about all payments having to go through them - because if they open up any other method, the natural flow of the millions of developers and apps would be for all of them to switch to that other method that shifts more of the money to the developer.
Apple likes to make money, of course, and their angle on doing that is to make products and services that cater to the customer’s needs - easy to use, simple to understand, well supported (note that super-inexpensive wasn’t on that list). But sometimes Apple’s ironclad App Store policies are actively unhelpful to those customers - things like not just being unable to link to the company’s website to sign up, but not even being able to hint that “you can sign up on the web” - that is absolutely a bad customer experience.
A lot of their other policies can be argued to be expensive for the user but designed to provide a good experience - the signup one entirely fails the “good customer experience” test. But there’s still that problem of, if you simply tear up that rule, then millions of apps switch to “free to download, tap the in-app link to sign up on our website for a monthly subscription”, and the App Store income drops to zero, while everybody still expects the App Store to keep running. I don’t know what the solution is.
If you don’t change the fundamental mechanism, the question comes down to the percentages charged to the developer, same as in retail. Is 30% too high? Maybe. I’ve seen cogent arguments both ways (I’ve also seen a lot of enraged rants that basically any number you might name is too high - I tend to discount those). I think it could be a bit lower (20% maybe? I don’t know), but sales / marketing / economics is not my forte.