Actually the closed App Store of Apple is the main reason why I would never buy an iPhone and other people should neither. Android allows you to install .apk files from any source. The problem with Apple is censorship. For example we have a very evil newspaper in Germany called "Bild". It is only read by very dumb people, but that is another topic. Until a few years ago, "Bild" always had a topless woman on the cover and that woman also appeared on the start page of the app. Apple is is from the US and topless women seem to be a problem there - unlike machine guns or hate speech. Apple threatened "Bild" to get rid of the topless women in the app. Otherwise the "Bild"app would have been banned from the app store. So an American company prevents German citizens from downloading an app because of some strange American moral standards. Apple also banned an app that made fun of Jesus, which is not a problem in Germany either. Here in Germany "Die Hard" was on TV on Good Friday every year for many years, but Apple prevents us from installing apps that make fun of Jesus. There are more examples like that. Apple treats people like kids. Everybody should decide on his own what he wants to install on his phone, because he owns it.
Honestly, google throws apps as well. Just recently, they threaten to shut down a whole bunch of apps...
Censorship isn't nice of course. But it happens all the time. Bild wasn't offered by a lot of distributors back in the days... as student I worked in a grocery retail for years. We weren't allowed to sell Bild newspapers for quite a while, so what?
Apple developed iOS, takes care for its evolution and covers ALL the R&D costs. Its their system, so they get to decided what they offer or not. That's business.
I don't get what people get upset about with android/ iOS. Imagine, somebody opens a retail store (that's what the app store and playstore are) and a third party walks into your building and says: "well, you should let me sell my stuff here. Btw, I don't wanna pay rent because I believe this should be an open space for everybody....
If you don't like android/ iOS, don't use it. Or create your own system, nobody will stop you from doing it...