I didn't know that about S3! I'm referring to supabase storage though, which does have the concept/option for buckets to have folders within them. Unless I'm missing something?

The UI creates and hides fake empty files to act as a “folder”. I’m really not sure of the value of this in an app with multiple users unless you are giving them all a similar ui versus just keeping their files separate with a path. This link talks about what they did in the UI. https://supabase.io/blog/2021/07/27/storage-beta