Comment by mlaci

Yes, but in that case you need to reencode every video in realtime at playing. Maybe you speed up the process with capturing the different parts of the video in parallel and concatenating the parts in the end, but if you want good compression then you need to reencode the whole video again. This is far from just getting a video file from a CDN server. If you want to try it, just few line of code with MediaRecoder API in any browser.