A union scrum is NOT just a way to restart the game. Is a game moment when the ball is contestable by both teams, and the advantage of feeding the ball should be little enough to ensure that. If referees don't pay enough attention on this, that's just a case of bad refereeing one part of the game, not the denial of the purpose of playing a scrum.
If one team cheats in the scrum to mask its weakness is a very good thing that free kicks and penalties come out to punish them.
If you don't like that, fair enough. Rugby League has chosed a different path from union and you are apparently happy about that, but let union play as they like it.
I think that most people, myself included, would question the extent to which RU scrums at the highest levels of the game are really contested these days. If they were contested, then I would expect the ball to be put in straight (something most refs seem incapable/ uninterested in policing) and for there to be more heels against the head. As it is, most of the srummaging action I see on TV seems to involve props not binding properly and scrums repeatedly collapsing - my own theory is that modern rugby shirts are not fit for purpose for props since there is no excess fabric to bind onto. Further down the RU foodchain, I understand that scrums are definitely more contested, just as games tend to be a bit more open.