> For example, randomly jumping in a text page won’t tell you where you are now in relation to the previous position.

That's what scrollbars used to be good at, before they were dumbed down for dubious aesthetic reasons.

Right.

On Gnome, when I switch left/right between virtual workspaces, the animation provides some indication of the switch.

When I tried xfce, there was no animation, it didn't feel like an improvement.

Perhaps this is down to preferences.

It's useful the first few times, and annoying time wasting all the thousands of times after that. Animations should only be included if there's an easy way to turn them off.

How is that 20ms, or even less constitutes waiting?

I've never seen a UI animation that quick. Most UI animations are hundreds of milliseconds. And even if somebody did make one, it would still be annoying. Even a little latency is enough to break the sensation that the computer is part of my own body, and instead make it feel like a third party I'm commanding.

I can’t see I’ve ever felt like a computer is part of my own body. And I’ve been writing software for close to 40 years.

Either you’ve been using only crappy computers/software then or you’re not getting what they’re talking about. Do you feel like your car is an extension of your body when you’re driving? Because science showed that’s exactly how humans behave when driving. This is how our brain works with automatic motor functions.

Literally nothing happens instantly in real life, why should it be different with computers?

All hands tools (including common things like pencils and toothbrushes) react to your movement with zero added latency. Computers should be the same.

>Scrolling through does.

Yet "smooth scrolling" is latency, and to most who are already used to scrolling, it is extremely unpleasant.

When one does scroll (i.e. move the viewport of a larger screen that's being presented through the inside of a window), it is because one wishes to already be seeing the target position.

Any latency through added animation destroys the illusion.

I quickly close any webpage that forces that strong discomfort upon me. And switch away from any application that does it against my wishes.

Though “smooth scrolling” that interpolates between detents is a considerably different creature than “smooth scrolling” that tracks touch and has inertia resulting from it. The former is like nails on a chalkboard whereas I find tracking/inertial scrolling quite pleasing with how it lets one use muscle memory to “fling” the page to a particular point with decent accuracy.