If they reset their stats permanently, it would mess up the entire leaderboards
Instead they should have a option have new stats shown, that would be shown publicly. They're old stats would maintain they're places on the leaderboards while people could still see their old stats through a button or something. The new stats could be kept or reset every month or so, while all the wins they get in the new stats will still be counted in the old stats.
(If you get this plox tell me XD)