why "delete" key does not work on mac

The "delete" key changes the action depending on the context.

• While viewing the library in the Moments, Collections, Years, delete ⌫ will suffice to delete a photo from the library.
• While viewing an album or smart album or a project the delete key is bound to "remove from album/project". Then you need ⌘⌫ to delete a photo from the library.

There are different situations - in some using the delete key does move the photo to the recently deleted (deleting from Photos for example)

In other situations like in an album it removes the photos and command delete moves them to the recently delete album - two different situations and two diffent needs

As to "Why" - no one here knows "why" anything - we are users like you and can tell you "what is" but can not tell you "why" and such discussions are useless and forbidden by the TOU you agreed to

have a nice day

LN