Is device/browser compability and flash fallback provided with the default embed? Compability Chart?

Hello, could you confirm that the most browsers/devices are supported with just using a WELL ENCODED MP4 VIDEO and the DEFAULT JAVASCRIPT EMBED code is enough provide the video? I've read a lot about different video formats. The web can't decide which to support, which not. New formats try to get the crown, but in the end nothing changed. In 2016 I think most browsers and devices support a well encoded mp4 video. But of course older Internet Explorers need their flash fallback. Also there seems to be a bug with older iPads, where a lot of people write about. Is this all solved with the default javascript embed? :-)