I want to use my compute resources for stuff that are actually useful/relavant. I have no problem if somebody makes some animation that actually conveys something relevant for the topic of the website/product/article etc, eg some animated plot to showcase some data, esp when that can convey more than a classical visualisation. To be fair, I also dislike hero images in general, as they are distracting/useless, consuming bandwidth resources and screen space (esp in mobile). But "hero animations" take this a step further.