APPle's system is closed (you can only escape from prison if you want to open it, but there will be security problems), so you can only download and install the APP on Apple's mobile phone from Apple's special APP Store, and the app from unknown sources cannot be directly installed on Apple's mobile phone (I think Apple's approach guarantees the safety of users to the maximum extent).

The closeness of iOS is Apple's brand advantage. In fact, Apple's iOS system has always been very closed. Except for its own self-derived products such as iPhone, mac and iPad, no other brands can use it, which keeps the closure of Apple's own iOS system, so it can completely adapt to its own hardware devices and finally let users get a smoother experience. This is the competitiveness of mobile phones such as iPhone, and naturally it cannot be open source.

Once Apple opens the source code of iOS, it will break its own ecosystem, but it will not be worth the candle. Although it is true that Apple can let everyone use the open iOS system, you should know that in this way, you must accept the transformation of the iOS system by Android phones, just like the Android system given by Google, in the hands of Huawei, Xiaomi and other mobile phones, interactive systems such as EMUI and MIUI have been derived. Although the source is Android, "bad taste" will break Apple's ecosystem construction.

IOS is Apple's biggest iconic feature at present. Without the advantages of the system, Apple's word of mouth will be difficult to conquer the market. We should know that Apple's efforts and contributions in technological innovation and appearance innovation are not even as good as Android phones, such as dual cameras and full screens. In fact, Android phones were first proposed. If Android phones can realize the same system as iOS, the price will be half cheaper. I believe that many people will no longer choose the iPhone, and I believe that Cook will not be "stupid to this extent".