(A)PNG supports semi-transparency. In GIF a pixel is either full transparent or full opaque.

Also while true color gifs seem to be possible it is usually limited to 256 colors per image.

For those reasons alone APNG is much better than GIF.

PNG uses deflate (same as zip) but GIF uses LZW. These are different algorithms. You should expect different compression results i would assume.

Remember when we unwillingly trained the generative AI:s of our time with an endless torrent of factoids?