It's probably not what you're looking for, as it's proprietary & closed-source, but I've found AnyDesk to be pretty smooth. They have a free tier for personal u

It's probably not what you're looking for, as it's proprietary & closed-source, but I've found AnyDesk to be pretty smooth. They have a free tier for personal use. I really only use it to help out my parents when they can't figure something out on their computers, but one advantage is it's very easy to walk a non-technical person through the setup process, without knowing anything about their network topology. For my own gaming I used Parsec for a long time, which does stream pixels but has pretty impressive variable rate compression.