The thing is apple doesn’t need to charge developers an exact number. Bandwidth is extraordinary cheap.
There are extraordinary easy baselines they can implement. Plus any RnD is already recouped years ago for the AppStore.
1: free apps can be listed for no cost.
2: add supported apps can have a 0.001$ per download
3: apps costing 0-5$ with IAP can have a 0.01$ per download
4: apps costing 6$> are free.
Or an even simpler implementation would be.
1: free apps with no adds are listed at no cost.
2: every app sold or using adds/ IAP pays 0.001$
Of course apps paying the 15-30% fee(or whatever the will be) gets benefits that apps not using it won’t get and obviously compete to provide this.
You missed my points about bandwidth. Either you charge the exact amount or you charge based on a tier. If you charge via tiers then some people are being overcharged and some aren't. So that becomes unfair on some people. And those people will grumble, and we'll end up in exactly the same place again.
Why should free apps be listed for no cost? You're saying Apple should be charging some apps for their bandwidth but not free ones, whilst simultaneously saying apps should be charged per download.
You've listed charges for various downloads; how do you know Apple isn't already doing this? Their 30% cut covers the bandwidth, staffing, legal, data centres, energy, app reviews, marketing, customer service, developer apps and OSes, etc.
Also, if "any RnD is already recouped years ago for the AppStore", how do you think it was recouped? It was by charging a commission (that they are fully entitled to do). You're saying that because the initial R&D has been covered already then they should stop charging developers 15-30% because they're, what, a charity now? It's their business. They set the commission that covers their costs and probably gives them some profit which they tcan then reinvest in other things. If you think Apple should be doing stuff at cost then there'll be no money to invest in future hardware and software, new devices, better technology, and so on.