I often think there's a general problem that rugby wants to be seen as entertainment, but pinging all offenses at the breakdown will make for a very stop/start game
Referees are criticised for being whistle heavy (CMK), whereas others are praised for allowing lots of offences to go unpunished and allowing the game to flow (Barnes, Owens)
Players largely don't care about the spectacle. They want to win and will continue trying to get away with things where they can get an advantage
Referees don't see everything, but typically choose to let some things go based on guidance and in the name of entertainment
Getting that balance right is incredibly difficult.
It feels like the guidance right now is to be stricter on the areas that can directly cause injuries to the head, and that's not a terrible thing
Referees can't do this alone. If the game wants a cleaner breakdown, the clubs and players need to start it. The players need to be coached to obey the laws rather than bend them, the players need to try to stay within the laws, then the officials can penalise those that overstep the mark without every game resulting in a whistlefest.
The alternative will be lots of boring games and complaints of everything becoming a kick fest and being won by penalties.
And/or referees giving cards for minor breakdown offenses.
It really has become a mess