GPU passthrough on Proxmox VE host enable the guest to provide bare metal like experience - no RDP, no streaming. This creates a limit that per GPU could only be used in 1 guest, but it is still powerful while easier to configure and requires less advanced GPU.
Proxmox VE is an 0pen-source software server for virtualization management. It is chiefly designed for servers, but it is also great for workstations. Imagine you can have separated workspaces that run different operating systems, and they can run simultaneously!