From what I understand (and note that this is unsubstantiated, because we just simply don’t have the same size userbase/activity here), while lemmy is fairly good, piefed is supposedly even better.
Better in terms of lightness? I would be extremely surprised given the vast difference in performance and resource consumption of Python vs. Rust, and because apparently Piefed already has more features than Lemmy does. But maybe I misunderstood your point.
Citation?