Every other platform does this in the back end yes. It would be great for Nostr to see a good video handling system, but it's yet to come about. Supporting HLS would be fantastic. I saw so many vlogs that where 5 minutes long and 2GB, while I encode full 2 hour movies at half the size.

If Nostr video ever wants to take off this needs to be solved. I've been banging this drum for months.