Well, this is the exact opposite of his point. Of course it should make sense when not animating! That is given. The entire crux of his point is that it should also make during an animation.

In an ideal world, it is hard to argue with. Yes, sure it should make sense. But also, please don't spend precious cycles on this unless all the other bugs are fixed, and this animation consistency is truly the most important remaining issue to address.

It's like you read until that point, but then didn't read the justification for why it makes sense to care about frames during the animation, the author does outline a bunch of reasons why it should make sense during the entire thing.

Maybe I've just spent too many years as a pixel-perfect chasing frontend developer, but things can look very janky if they jump out of place during animations, compared to where they are before/after.

But the author tried to show exactly that, if screenshots during animation don't look sensible, it points to animation as a whole not making sense - it being either messy, overlapping, or confusing - and, in general, eroding the user's trust.

I first heard something similar taking motion design classes in art school: every frame should look good. Transitions and animations that have bad in-betweens look bad overall