The biggest place we play (+700) has no stage. Management sets up velvet ropes to indicate what part of the floor is ours. I often feel like a doorman during setup.
Of the dozen or so venues we play, about half of them have stages, and a few barely rate the name: old pallets with a couple sheets of plywood nailed to them. Painted black, so they'll look intentional. At this stage of things, all I really care about is not tripping over cables.