If you want to go irons only for a retro build or because you don’t want to spend the money on a quality optic, or if you just want irons, there’s nothing wrong with that. I’ve found that it is easier for people to learn irons first.
But the right optic is a superior sighting system. RDS’s are better in low light. At distance, magnification is always a plus.
An amateur trains until he gets it right, a professional trains until he can't get it wrong.