It's neither, I think it's just that different fields operate differently. In CS most papers are published in conferences. Authors do their own typesetting, editing, figure making, etc. Peer review is organized on a volunteer basis by the program chair, who is (as far as I know) not usually compensated for their efforts.

This means we don't get many fancy videos unless we or our university's PR people make them, but it still seems to work fine for getting science done.