The problem with the animations are not that they are bad, per se.
They do provide a visual guide to new users of what just occurred. That has value for the new user.
The problem is that too many systems/programs that provide these animations forget that the animation that was useful to one as a new user the first few times, becomes an irritating time sink when it has been watched the ten thousandth time. After the ten thousandth time watching it, many users already know what is going to occur, and just want it to occur and move on. But the system/program provides no "turn off animations" profile setting. So when one gets to the point that one no longer needs the animation to inform of what occurred, one is still forced to sit through its delays. That is the big problem with animations.
Real world example. My Android 7.1 phone came with all the standard android animations turned on at the outset. At some point after having it for a short time, I discovered the animation time adjustment settings inside the hidden developer menu. After I set them all to zero (i.e., do not animate) the phone suddenly felt like it was 1000% faster.
So, in this case Google did include a "turn them off" feature (good). But they hid it inside a normally hidden menu inside the settings app (bad). Why was this hiding of this setting bad? Because most users will never find the developer options menu (because it is hidden) and therefore will never know about the "turn off animations" settings that could make their phone feel significantly faster immediately. So most will be stuck watching animations that make their phone feel slow, even when they already know the outcome and no longer need the assist provided by the animation.