It's every action on Mac and iOS that does this, and it has been increasing in intrusiveness for a decade. I can't be sure why they do it, but it comes off as though their visual designers are immature, thinking we want to see their impressive animations not just in a demo, not just in a tutorial that we go through once, where we are meant to grasp the relationships between the things, but over and over again, all day long, for decades.

I freaking don't. One time was plenty. I don't want any animation. And the "reduce animation" feature's implementation is a slap in the face: all the delay -- that part is non-negotiable apparently -- but with blurry crossfades instead.