> And iOS isn’t a platform that you could.
Of course you could. Apple would simply have to enable it. The fact that you can't download an app through Safari on iOS is simply an arbitrary decision by Apple.
> If side loading is important to you, get an Android phone or maybe a niche OS phone.
This has little to do with individual user preference about side loading. This is about developers who want to get their apps into customers' hands. While I'm sure a lot of developers and companies would be tickled pink to not have to develop mobile apps, its their customers who expect those apps and a very significant number, if not a majority of those customers, are iOS users. So while we can say it is a choice to develop iOS apps, it is, for all intents and purposes, a competitive requirement for many developers.
So even if a customer is already aware of you, already aware of your app, even if you have no need for Apple to distribute, market or host your app, you are required to have them do so and pay Apple's 15% or 30% fees on everything between you and that customer, in perpetuity, just because that customer is forced to use Apple's app store to locate and download your app.
It's worth noting the contrast between that situation, which is the source of most of the derision over Apple's fees, and a situation where a developer is producing a mass-market iOS game from scratch, in which the app store listing is actually an asset, in which they DO rely on Apple's distribution, in which they DO rely on Apple's marketing, etc. yet they get away with paying $99/yr, which Apple apparently considers adequate compensation for the above services they provide, and Apple doesn't touch any of their ad revenue, regardless of how successful that app is.
Even putting aside the completely unnecessary and arbitrary walled garden, that inconsistency in Apple's taxation of developers is worthy of criticism.