That $100/year is more of an entry fee. Since Apple controls everything from the hardware to the OS to the software and the App Store, all the money just goes into one giant pool and it's quite the grey area as to what pays for what exactly, which is why I am not a fan of cutting it so cleanly.
Like Maps, iMessage and Siri are free (in that I don't need to pay a separate fee, but they are clearly not free to develop and maintain). Is the money supposed to come from hardware profits, or App Store revenue, or somewhere else?
People like to point out that 30% is more than enough to pay for the costs of operating the App Store, and it suits their agenda to argue that everything could in theory be subsided via iPhone profits alone because who doesn't like free things? But everything is inter-connected, and it can also be argued that it is because of services revenue (eg: App Store commission, Google's $35 billion annual payment, Apple one subscriptions, even Apple Pay) that allow Apple to sell their hardware at their current prices, when they might in fact be even more costly? I know it's hard to imagine that iPhones could be even more expensive, but my point is that none of this exists in a vacuum.
Even with the App Store, the reality is that the bulk of their 30% commission comes from taxing freemium games, so in reality, what all of you here are championing is that the companies behind IAP-riddled games like Diablo Immortal, Fortnite, Clash of Clans and Roblox be allowed to keep more of the money that they are already making via pretty questionable practices. Personally, Apple could tax them 50% and I wouldn't shed a tear.
It's very easy to just tell Apple to comply with whatever demands the EU makes of them. What I am observing is that Apple is instead taking the time to re-evaluate each and every ecosystem feature that the EU has asked them to make available to third parties, and we can see that Apple is not opposed to simply withholding said feature from both third party OEMs and their own customers, if they feel it's not worth the cost of compliance. So users and smaller businesses won't always come out ahead at every turn.