There are too many ads in Sydney................Stop the clock for ads = bigger TV contract.
Agree totally with OP
Mandatory stoppages for when the ball goes dead in goal, in touch, after a try is awarded or a penalty kick at goal is taken would bring many benefits such as less pressure of refs to call time off if he thinks a team is deliberately wasting time, create more advertising opportunities for broadcasters.
As long as there is a type of "shot clock" for these stoppages, e.g. 30 sec to take a drop kick, form the scrum etc, as this would stop games dragging out for too long.