It doesn’t automatically make you a better shooter. It just helps you be a better shooter.
I haven’t shot a match in a good while so I can’t gauge it anything by that. But I could tell right away that I was better at longer shots (15+ yds or so), and after some practice finding the dot I’m faster on multiple targets (steel). The biggest advantage to me is that for years, and even now, I would always try to see over my sights and look at the target. With an RMR, that’s eliminated. Just look at the target and put the dot over it.
You’re probably going to be just fine if you live your whole life without an RDS, but there’s no reason not to get one either.