Hi Alixander! I started using D2 just a couple months ago -- the first time I had to design a system at work. I'm really happy with it -- I was amazed how easy it was to pick up.
TBH, I don't think these fancy animations are necessary. If I want to call attention to a certain box or arrow in the diagram, I would rather turn it red than have anything moving.
There's another HN discussion going, about declarative diagramming [0], from where I learned about Ilograph [1]. And which makes great use of animations for system documentation.
I think diagrams are opinionated. I’d like to show animations instead of just colors. Data flow for example. Yes arrows help, but animations help better. It is all about personal preference. There is no right or wrong.
TBH, I don't think these fancy animations are necessary. If I want to call attention to a certain box or arrow in the diagram, I would rather turn it red than have anything moving.