I just updated from Mojave to Big Sur and my computer seems way more responsive now, especially Lightroom and Photoshop, which had gotten painfully slow before. I have not made any other changes to the computer and periodically run computer maintenance processes with Clean My Mac. Can anyone explain why the slowdown occurred and why updating the OS fixed this? I have never before experienced such a dramatic shift in performance from updating an OS with the same computer. The computer is a top-of-line 2017 iMac, if that matters.