Perhaps the ideia of a back-end was the video selection, so everyone watches the same videos.
But there could also be a video list in the source code, or maybe, but less likely, a deterministic usage of yt's algorithm
I'd say the best part is not needing screen on the server.
If you have several servers and several people that like several multiplexers, you would need to install all of them in each server, and manage configuration etc.
However, you can have your own multiplexer and use shpool on a window to connect to a server.
Done, you have your favorite multiplexer, with your configuration, and the only tool in the server is shpool