The entire point of the app store is to further concentrate power with Apple.
Whether that is good or bad short term or long term can be debated separately, but it is fundamentally a shift of power away from independent developers towards a giant megacorporation. (I personally think app stores are fine but that the public has an interest in preventing any entity from having too much power, so it should be illegal to prevent sideloading.)
The point of the app store is to have a centralized AND TRUSTED distribution point for apps of the OS.
People can install non reviewed apps by using non-official app stores. There is good reason most people don't as these are plagued or perceived to be plagued with malware.
