Of all the things they do, that is not one of them. How long does it take from pressing a folder to showing its contents on iOS? How much faster would all of it be without a fancy fade in/out animation? or shrink to dock, or anything else in the UI that takes longer than it has to because it looks cooler that way.
I find that there’s always an option in accessibility settings to reduce the overall fanciness or anything that I find jarring on iOS. Here I believe settings > accessibility > reduce motion will apply.
Nevertheless it’s nowhere near the powerful experience that was palm OS when it was selling palm pre and the like
It's funny because in Android you can set animation speed to 0.5x or even turn them off entirely, it's an option in the developer settings. Apple would never let you do that.