Why I can browse my Photo library (camera roll) in iOS 14.3 with Wish mobile app with no permission?
Here is a short explanation. Wish uses the PhotoKit technology provided by Apple, and more specifically the PHPickerViewController class. It's the pop-up that allows the user to upload or take a picture.

Since iOS 14, this panel doesn't need any permission to display your pictures, since you have to select which one you send to Wish (or any other app); nothing is sent before you select them.
No need to worry, Wish can't access your pictures/camera or your cloud storages!
If you want to learn more about the Photo picker here is a WWDC 2020 video : https://developer.apple.com/videos/play/wwdc2020/10652/