In the past, maybe Windows XP to perhaps Windows 7 era it did — not sure exactly when they stopped using primitives. But not since a long time. It's just (lossy) compressed bitmap streaming nowadays.

RDP on Windows from Windows now uses h264 by default.

Interesting. Here is some background: https://techcommunity.microsoft.com/t5/security-compliance-a...

I guess “by default” means if both client and server have the required hardware support and there aren’t too many concurrent sessions.