That's not what happens now and there's less chance of it happening if we stopped the clock. If you're suggesting the ref gives the ball to the other side when there is time wasting, we don't need the clock to stop, we can just start giving the ball to the other side now.
It wouldn't obliterate time wasting, because it would still be done to stop momentum and the flow of the game when the other team is on top. And also when a team is knackered and under the cosh they could use such stoppages to their advantage. If there's a clock that stops, then the ref isn't...