MOV is Apple's homebody: gorgeous on a Mac, awkward everywhere else. It was born in 1991, Apple's QuickTime team, and its real weak spot is traveling: Windows, Android and the web would all rather meet an MP4.
MP4 is the world's default video: the file that plays before anyone has to think about it. A container, most often carrying H.264 or H.265 video with AAC audio. That makes it the right destination when what you need is playing everywhere: browsers, phones, TVs, editors, slide decks.