It might be a bit esoteric ... but the Photos that shipped after macOS Sierra introduced a clever new editing view built upon, I think, CoreImage so that it could do all the processing of levels, temperature, etc. extraordinarily fast — leveraging the hardware — for real-time changes as you dragged the sliders.

Unfortunately the retouch tool in Photos for cloning, fixing scratches, etc. took a huge step backward in performance. Like it became unusable.

So simply for dealing with old scanned family photos that have lots of scratches, tears, etc., I have stuck with Sierra Photos on my one machine.