That's up to personal preference. Just like with static wallpapers, some people like single subtle colors, some people like noisy multicolored wallpapers.

There's already subtle parallax in iOS etc.

Animated wallpapers could be subtle, like raindrops, or animate only when interacted with, when you're bored or waiting for the AI to finish a run etc. :)

> That's up to personal preference.

Stated preference perhaps, but unlikely revealed preference.

Depends on context, but for a computer on which you're doing work, moving wallpaper is usually a net negative for usability while you're actively working, though the magnitude depends heavily on the animation.

The problem is primarily peripheral attention. Motions is a strong pre-attentive visual signal: your visual system detects it without you deliberately deciding to look at it. One a laptop where you're close to the display and spending long periods concentrating on text, code, documents, etc., any visible animated region around or through windows can create low-level competition for attention.

A good compromise is wallpaper motion during transitions or stillness during work.

Broader UI principle: motion should explain change, not create change to be noticed.