Does it also play a huge part in the advancement of computer graphics in general? As I've often understood it, the demo scene people were usually some of the most talented in their field.
Not a huge part, at least not directly. Many sceners do work in the graphics industry (cgi, games, hw etc) but demos are mostly just a hobby for everyone. I feel like lots of stuff done in demos is not really practical for "real-world" use.
There is one interesting example of where demoscene has managed to break into more commercial world: https://www.notch.one/
There is one interesting example of where demoscene has managed to break into more commercial world: https://www.notch.one/