1. My number one wish for Apple with their OSes is to just keep everything up to date and developed, with concentration on fixing bugs.
For example Weather, Clock, Contacts, Voice Memos etc are barely updated and they all buggy. Widgets are half done and they do not work well with Siri.
2. I can't imagine that Siri will be fixed, but it's just a pathetic failure. It is especially bad for any multilingual or multi-country set up. There are so many low hanging fruits that Apple does not address for years.
3. Achilles' heel of Apple is search. Anything search related is very poorly done. Search in files, search in Music, search in AppStore are failing basic functionality.
4. There should be some way to enter an admin mode so you are not prompted for passwords dozen times in short time.
5. Limited Contacts sharing mode, similar to how you can share only a general location with some apps.
6. Folders on the Home screen are outdated, and it's too finicky to work with them. I wish that would improve
7. Better synchronization. I still have to do so many of the same things on many devices. All those should be saved in the cloud and be in sync (with an option to make an exception on per item, per device basis)
8. Messages, FaceTime and ScreenSharing need to merge into one communication app.
9. Better family photo library capabilities
10. My last wish is about a decent music app, the one that works, and allows me to use my collection. I am not sure if it's required to separate it into two apps, one for Apple music and one for My Music, but what they have right now just does not really work well at all.