It mostly did before V8 was created. A few people ran JS outside the browser using Mozilla's Rhino, but it wasn't very common. Nodejs probably was the first widely adopted platform for non-browser JS, and it was built on V8 after V8 already existed. So I believe historically server-side JS did not drive JS performance.
It should be mentioned that Microsoft has had server side Javascript (well, Jscript) running on IIS since 1997. I used to write data driven websites in it.
