I still haven’t figured out the magic codec I can plug into ffmpeg so the self hosted videos on my Wordpress work on all web browsers (i thought h264 would do it but mobile still doesn’t like it) gifs are designed to be portable and work every time
In contrast, if your gif is over 1MB, my mobile browser will not display it. This is done to prevent excess data use. (It's a uBo ruleset)
I'm unsure what browsers will still not support h264 however. Most commonly you'd find webmasters using both webm and mp4s in their video sources to allow the benefits of the webm filesize, and the mp4 to support ios devices