What do you use VNC for? If your local network speed are fast, you can easily code or browse ... etc - if you are watching videos or playing video games forget about it.
I have no real use-case. Just making a statement. I wonder why YouTube can stream 1080p at 60fps but VNC on a local network can't.
Not bitching about VNC because it's done a lot of good things and it's very useful, but I think there's a lot of room for optimization.
Try using Steam Streaming - it's some work to get it to mirror a desktop rather than a game, but because they assume high-bandwidth connections, it does 1080p at 60fps for me, with super low input latency.
Videos are pre-rendered and compressed which massively reduces filesize
Can't the same sort of compression be used over VNC?
That would help.
YouTube has the luxury of not needing real-time compression. Latency hurts usability more than low frame rate.
OK, but how does Apple's AirPlay work so well, then?