The default delete behavior is not that, and it is explicitly documented as such.
> When you delete photos and videos, they go to your Recently Deleted album for 30 days. After 30 days, they'll be permanently deleted.
> When you delete photos and videos, they go to your Recently Deleted album for 30 days. After 30 days, they'll be permanently deleted.
Additionally, at least in iOS 17.5, the Recently Deleted album itself has a disclaimer at the bottom that says that “items will be permanently deleted. This may take up to 40 days.”
The whole thing feels like it's running on duct tape, wishful thinking and a large chunk of non-technical users that would blame themselves rather than the shitty tech when weird things like this happen.