Why my iPhone storage is full when I have deleted my photos
Why my photos are taking too much space
when I have deleted most of the photos
iPhone 12, iOS 14
It might not be your photos that are taking up the most space. You can check what's taking up your iPhone's storage by opening Settings > General > iPhone Storage.
You can read this article for a more in-depth explanation of this: How to check the storage on your iPhone, iPad, and iPod touch - Apple Support
-- Jay (they/them)