This spell is both more and less useful than in PnP.
In combat it makes an enemy attack its allies AND auto-kills them once all other combatants are dead. That's pretty powerful, even with the advantage on the save.
On the other hand, it can't be used to interrogate someone, for example, or make a boss call off its underlings.
In a PnP situation, if I managed to charm a cult cleric, I'd want to talk to them, have their thugs back down, and get them to tell me what's going on.
Even old-timey Baldur's Gate had instances where you could get information from an enemy you charmed by talking to them, and that game was made a hundred years ago. Surely you can make charm a more interesting tool than just another combat mechanic.