Comment by LadyNike

It's just very different.

For example, there are a ton of SDKs that provide push notifications, such as Baidu, Tencent, etc...

There are also "super apps", such as WeChat, that offer their own API surface and can be preferable to some app devs.

Then there are some things, such as "advertising id", which none of these SDKs provide (at the moment?).

So yeah, the answer is somewhere between "it's complicated" and "no one".