I clean cases to preserve my die life; less scratches, less abrasion.
I have trimmed case batches, but
overall accuracy enhancement was definitely not worth the time (except in certain revolver-fired applications).
If I shot Bullseye I believe I'd at least sort by length........
Not moot; got a few thousand just-cleaned 9x19 used brass to load. IPSC summer.........
(but I AIN'T trimmin' any!)
(I have worn out sizers, but the companies replaced them.)