However my issue with iOS is, that people don't have the freedom to choose whether or not they want to be protected by this "walled garden".
Currently, you cannot opt-out, and the side effect is that Apple limits our freedom to choose to, for example, set Firefox as the default browser. Or set startpage.com as the default search engine in Safari. etc. etc.
I don't understand how a single company is allowed to have so much power to decide/enforce upon us what we may and may not do with our devices. And since it's an oligopoly (Apple or Google), we don't have any other alternatives.