Animation earns its place when it explains continuity, consequence, hierarchy, progress, or recovery. Everything else competes with the task.
Motion should answer a question
Where did this object come from? What changed? Is the system still working? Can the action be reversed? A transition without an answer is visual noise.
What question does this transition answer?
Timing is part of state
Immediate acknowledgement, honest progress, and a stable completion state matter more than an elaborate flourish. Latency should be explained, not disguised.
Does latency remain honest and understandable?
The physics belong to the product
A financial product, industrial control surface, consumer fitness app, and AI workflow should not share the same elastic easing because it is fashionable.
Does the motion fit the product's consequence and material?
Reduced motion is a complete mode
Accessibility is not achieved by switching every animation off and leaving state change unexplained. Provide another cue for continuity and consequence.
What cue replaces motion for someone who has reduced it?
Good interface work makes the decision, evidence, owner, and consequence easier to see.