This issue seems to be a throwback to MS-DOS. The ‘rd’ command to remove folders prevented you from removing them without ‘del . /s’ being run first inside the folder. I think it was to prevent inadvertently deleting a folder full of files. In the world today we have recycle bin and undo, so I’m not sure that reason is valid any more.
TL:DR; asshole design
Liftoff for Android is better than Lemmy imo having tried both, there are less annoying quirks.