Well...without unpacking all of your self-preferential language and logic...this is one of the core problems to your argument.
The idea that Apple has "no fee for themselves" is to ignore all the costs involved in their business. It ignores infrastructure costs. It ignores development costs. It ignores employment costs. It ignores legal costs. It ignores marketing costs. It ignores R&D costs. It ignores every single cost of business that Apple has.
The statement that Apple has no "fees" is so obviously ridiculous as to question the seriousness of any of these efforts. It's like an activist's fantasy of how business operates. Not a serious discussion.
I've worked in politics my entire professional career. I've seen all sorts of naive discussions of business and policy initiatives proposed, discussed and written by people who have no basic understanding of how things work. And the DMA is right at home in that category of naive regulation.
The actual question is how can Apple compete when it bears all the costs and fees while the DMA is granting these services free to any business who wants to take advantage of Apple.
The DMA is not a serious piece of regulation. That doesn't mean it doesn't have power. It does. It has the power to make a big mess.
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But the core problem to all the extensive content you're posting is that you're simply relying on the fallacy of authority. You list large swaths of language from the DMA itself; all sorts of bullet points and indented paragraphs and legalese, with the idea that it's impressive enough to back up your arguments. But at core, the basic philopshy of the DMA itself is intellectually bankrupt. It's bald protectionism that is meant to try to help the EU stay relevant in a market that it has failed to cultivate through means of tech innovation and sound business principles. As I've told you before; I get the effort. But it's an attempt to take a shortcut to trying to be relevant in an industry that it has failed to build within its own borders.
Want to compete in Tech? Then compete in tech. The EU will never legislate itself into tech relevance.
I think my issue with this stance is that clearly Apple’s model has been, even if not initially anticipated, that they used the App Store fees to help fund all the costs of the hardware. Apple has had class leading SoC’s and I imagine they were able to do this thanks to that additional revenue that can’t be had from hardware sales alone.
Additionally, while other OEMs (excluding Google) just have to make hardware, Apple also has to fund the development of software and APIs that make the device worthwhile. Should they have to charge a subscription for iOS to fund these developments instead? That’s clearly not how Apple wants to frame their product or experience.
Depending on how it works, this seems to then allow developers to use Apple’s APIs for free - in this magical world where App Stores can do whatever they want. That’s before we get into, as someone else said, the social engineering of scams and fraud that will happen on the other stores. It doesn’t matter if the current model is all that 85% of users need.
We don’t even know what the scam looks like because it doesn’t even exist yet, but we’re already seeing scams where people are mailing $20k cash boxes as “refunds.”
I don’t think it’s too crazy to assume new app stores, if allowed to behave freely, won’t encourage most of this, even potentially mimicking the look and feel of the current App Store. Maybe a fake “Face ID to pay” or something that shows one amount but charges another even. I used to do IT support, both B2B and B2C, and I can see a number of my past clients being vulnerable to scams like this.
Then there’s the issue of security. I am very concerned about the security of iOS as a whole with App Stores allowed to do what they want. This could lead to apps that are able to break the sandbox, read from other apps, or read the iOS Kernal - as has been done in the past. I imagine it’s been more difficult due to apples tight sandboxing. I wonder if, by allowing anyone to get any app they want with any code onto “any iPhone,” how secure the kernal and core of iOS will be.