This is kind of simplistic. For instance, if ‘most people’ only watch the first 2 minutes of a 20 minute video, you still have to encode all of it for that mino

This is kind of simplistic. For instance, if ‘most people’ only watch the first 2 minutes of a 20 minute video, you still have to encode all of it for that minority that does watch the whole video. Also consider that very large groups of people use very similar hardware and connections. Anyway, of course videos are already chopped into chunks that are stored separately. It’s much easier to distribute and cache these independent chunks. On demand encoding doesn’t change that.