It's currently by design that folders can't be deleted. Too high of a risk of users accidentally deleting important folders. The app can't move files to the recycling bin, so any file/folder deletion would be permanent.
Viewing post in Can't delete folders in SMB?
I understand the reason, but I think it can be done safely.
add a toggle in the settings to allow folder deletion for people who want it.
The file deletion popup already shows a list of files that will be deleted and that it's permanent. If there's too many files, just show how many files are being deleted.
I think after these two hurdles, if people still accidentally delete important files well.. It's on them