VNC is a bit dated, doesn’t support auth as part of the protocol, and doesn’t functionally support a lot things like dynamic screen resizing, and things like stream transport of audio.

Not saying RDP is necessarily better, but it is functionally faster at least, and implementations here are open source, not the closed MS version.

I don’t know much about the tech behind either, but when I’m using VNC it feels like I’m just remote controlling the mouse and keyboard on another machine via a series of streaming jpegs and when it’s full screen I either have to scale the display so all the elements on the screen are too small or too big, or have scroll bars.

With RDP it’s so smooth it’s like I’m on the other machine. RDP doesn’t just remote control the screen on the other computer, it creates a new desktop session formatted for the remote computer. Someone else can even use the other computer while you log in as a different user. I don’t know if VNC can do this but RDP can even forward local drives and devices to the remote computer, you could plug a USB into your laptop and have it connect to the machine you’re RDPing into. It’s so seamless that I often forget I’m using a different machine when I have it in full screen.

It uses compression and is generally going to be more performant. It also has better security though strong encryption