iPhone storage full despite paid iCloud storage
how do I make my iCloud storage my default storage ?
Question marked as
You cannot. Your iPhone storage is full because iCloud is a separate sync/backup service, not an extension of your phone's physical storage, meaning apps and large files are stored locally on your device unless you use features like "Optimize iPhone Storage" to store originals in iCloud and keep smaller versions on your phone.
Manage your photo and video storage - Apple Support