What’s going on here?
I don’t see millions of duplicates, and I don’t see any duplicates in your screenshot. Those all look like unique accounts, judging by the usernames.
Edit: There’s a video, why did you embed just the last screenshot?
And, that screenshot is showing the KDE Plasma System Settings – not anything at all to do with Dolphin …
@redstrate and @Franken14679, the embed doesn’t work:

becomes
That’s why I used an ordered list. I suppose I could have specified, though.