I assume you have some kind of indexed shifting.

I'm a little new to the indexed shifting... been using friction shifting for years. But, I've noticed a few things that seem to have a bit of a bearing.

The "B-Screw" adjustment more or less sets the distance of the derailleur from the cassette/freewheel cogs. You want this set as close as possible without it rubbing to minimized the flex in the chain between the jockey wheel and the cassette.

The Jockey Wheels also have a little of float in them. A little float may be good to help center the chain. Shimano still uses bushings on their upper jockey wheel, even with 11s, but now with a lot less float. Too much float, and the derailleur doesn't shift properly. On my "frankenbike", I ended up using one of those Chinese aluminum jockey wheels which helped a lot with shifting.

Perhaps a worn chain would also have more flex and negatively impact shifting.

The newer derailleurs also seem to have a lot stronger of a spring which may lead to more positive shifting.

Extra friction in your cables/housing could also negatively impact shifting.