Do I need a GPU for a terminal RDP connection?

Question

RDP

Conducted a test: Removed the restriction on terminal connections on WIN 10 (16 threads, 63GB + video card) and connected 30 users to it, each of the users emitted a transition through the chrome tabs, the video card of the "impromptu terminal server" was loaded at 50%. and the speed of rendering tabs was indistinguishable from being on a real computer.
Then I took a normal server, the Xen virtual machine had win server 10 (16 cores and 64GB), connected 30 users to it with the same task, and then terrible brakes started, the processor was loaded by 90%.
As a result, the conclusion comes that the terminal server needs a graphics processor, BUT I have not seen more than one server with a video card.
Are my conclusions correct or am I missing something?
Is page rendering happening on the server side? if yes, then in the absence of a graphics processor, the main one is engaged in rendering.