Xcodeghost alone infected hundreds of millions of people (including all Wechat users). Let's add up your examples.

The first one infected a few thousand. The second one spread on Chinese phones, not Google or Amazon phones. The third infected about 120k users. The fourth infected 1 million users. The fifth infected 10 million users.

So the Apple App Store infected at least an order of magnitude more users despite having an order of magnitude fewer users total. Why at least? Apple does not allow third party security apps on its devices, so there are likely to be way more infections that we just haven't heard of.