When it comes to VMs, most things are solved and have near native performance, but desktop graphics are not. Due to limitations in GPU architecture, you usually have to dedicate an entire GPU to the VM to have reasonable graphical acceleration. Qubes doesn't solve this either, IIRC the apps running in VMs are glued to the host with X11 forwarding without any acceleration support.

For what it's worth the Intel B50 supports GPU virtualization and software support seems to be improving quickly. Really hoping this blows the lid off over the next couple years.

It's planned to allow GPU for chosen, trusted VMs on Qubes: https://github.com/QubesOS/qubes-issues/issues/8552