Lack of apps

If you're looking for apps for iOS, look in the App Store app on you iOS device. If you're looking for applications for your Mac, use the App Store application on your Mac.

If you're looking for Android apps, I'd personally suggest you stick to the Google Play store. You can access that from your Android device.

The Mac App Store is for Mac apps only. Being available for iOS and Android, has no relevance on whether or not they'll be available for Mac, and as such would not appear in the Mac App Store if they are not available for Mac specifically.

You cannot run iOS or Androids apps on a Mac.

Because they are available for the iOS and Android operating system, in no way indicates they would be available for the Mac operating system.