[maxst]

If you convert static GIF to static PNG, 99% of the time you'll get a smaller file. That was the original goal of PNG project, and it succeeded: static GIFs disappeared completely. Converting animated GIF to animated PNG leads to similar filesize savings.

[innagadadavida]

Video formats like webp exploit temporal and spatial similarities to get efficiency. Gif/apng do not. This reduces bandwidth costs and file sizes very much.

[maxst]

Download a dozen random GIF cinemagraphs, and try gif2webp and gif2apng on them.

[innagadadavida]

Try ffmpeg or vlc instead, you will get much better results. Ffmpeg has support for almost all video/audio formats ever invented.