Contact Nintendo and let them know you want this functionality.
Videos and audio do work in the Social Applet browser, but it can only play videos hosted on Google Drive, Twitter, or Facebook. It's a long process and probably not worth it in most cases, but can be done: https://browsedns.net/topic/1905/tutorial-watching-videos-on-google-drive
They are intentionally disabled in the WifiLogin Applet (which the browser that the DNS uses).