From what I gather, I don’t know that there’s a new norm in this regard yet, besides recognizing that gifs are increasingly old & clunky (despite being fun & amusing), and so I don’t know if mp4s or webms or something else might be better if wanting to keep a site lightweight while still having some animated elements.
WebMs encoded with VP9 or even better AV1 are better than GIFs. Decode speed is negligible, especially considering how much more quickly it will load