It's not a problem about permissions, I can erase the files.
The issue has nothing to do with being able to erase or not.
The issue is that I can't find a keyboard-only way to confirm the delete and it requires me to use the mouse to click on delete.
When you select a file / folder and then do cmd-delete, your hands are on the keyboard and it's very annoying to go back to the mouse to click delete.
For example, the same prompt on windows allows me to use the cursor keys, or tab, to select if I confirm deletion or cancel; so on Windows, I can do ctrl-delete, then right cursor (or tab) and enter and my file is deleted.
On the mac, I can do cmd-delete, then grab the mouse and click on delete; it seems like this prompt can be cancelled with the keyboard (with esc or enter), but cannot be confirmed with the keyboard.