The main issue is not the exorbitant commission rate. Apple is hurting the consumers via its anti-competitive behavior with regards to what apps people are and are not allowed to install on a device that they've paid for. They are blocking value creation up and down the stack in a manner that "if we can't extract it, you're not allowed to create it."
It's intolerable that Apple has been allowed to lockdown their device for 10 years, completely control the market for apps and when it looks like regulators will take action they reduce their price and claim to be acting in the interest of small business.
Third party app stores must be allowed. Apple should not be allowed to dictate what software I can and cannot have on my device.
My 82-year-old mom's desktop computer is riddled with spyware, browser toolbars, and other garbage. Her iPhone is pristine and works as well as it did the day she got it. That's because Apple refuses to allow that garbage to make it to the App Store.
Yes, there's some collateral damage for us nerds. And perhaps there should be an easier way to - for those who really care - install more low-level tools and apps. But it shouldn't be easy, and it shouldn't put the majority of users at risk.