As a kid, I just assumed it was aesthetic. Like, someone for an audience of non-musicians to project themselves on to.
As an adult, I recognize that this is almost certainly not the case. Presumably the conductor plays a role that is necessary and helpful to the rest of the orchestra... but I'll be damned if I can't quite figure out what that is. Surely its not just timing? Can't the players just... listen to one another to work that out?
It was critically acclaimed but I'm not surprised you haven't heard of it; it was overshadowed that year by the extremely lib Everything Everywhere All at Once. Cate Blanchett got robbed she should have won Best Actress. Tar should have won Best Picture. Should have been nominated for Best Sound, still can't fucking believe Top Gun and The Batman were nominated for that category but not Tar.
...Should have been nominated for Best Writing too, the only reason I can imagine why EEAO won that is the lib voting committee who doesn't watch any of the nominated films saw an image of that cringe ass tumblr-coded "In another timeline I would have loved doing laundry and taxes with you" scene and went 