Animation brings a whole lot more to explanations, making simple explanations of how request coalescing works easy to understand, token simulations [0] through to helping explain concepts like Fresnel lenses [1]. Embedding them into GitHub READMEs, tweets and documentation would be awesome.
Google do it to illustrate posts (e.g. https://blog.chromium.org/2021/03/a-safer-default-for-naviga...).
I found Excalidraw Claymate [2] but the stop motion approach with no tweening support makes it painful to create animations where circles move from place to place. There's also Manim [3] but I think this is more for maths.
Adobe Flash used to be the go-to; what do you reach for when you want to illustrate a concept with an animated diagram?
0. https://github.com/bpmn-io/bpmn-js-token-simulation
1. https://news.ycombinator.com/item?id=30576688