The effect conveys geometries and dimensions when activated that would otherwise require an animation. For simple objects this could save bandwidth and be resolution independent.

While I do not advise using it everywhere, it is just one use case that I do not have a problem with and that could be a useful part of a designer's toolset. Think of it as a 3D version of animated SVG. I only noted this because most other uses of WebGL are unnecessarily flashy and irritating.

And flatten the battery on my laptop/phone faster.

Huh? How are the pop out effects shown on the demo page irritating?

How are they not?

Seriously though, "irritating" is a matter of opinion. Explaining why something is irritating is like explaining why something tastes good.

Maybe my parents would think they're really neat and cool (as they have mentioned in similar things before to me), but I would object to that. While their claims of thinking that are perfectly rational from their own viewpoint (because they consider it novel and unique), I see it as an anti-pattern and distraction that gets in the way of productivity.

I can't tell whether you're being sarcastic.