the practical reason for this happening is that you can put images basically everywhere (github PR comments, emails, etc.), but these facilities rarely support

the practical reason for this happening is that you can put images basically everywhere (github PR comments, emails, etc.), but these facilities rarely support video. Video support on the net has until very recently been pretty awful too. Now that the video tag can be reasonably expected to work, in a couple of years we might have the tools to just embed video when we want to.