In golf they mow the fairways for a reason: You’re rewarded if you drive your ball onto the short grass; you get punished if you don’t.
Good iron play requires that you hit a high percentage of your approach shots from the fairway. That’s why I emphasize control off the tee. People say I’m a strong iron player. That’s nice, but it’s only because I play most iron shots from the fairway.
Golf is difficult from the rough. Unless you get a lucky lie, you can’t control your shots from the long grass, so you can’t hit greens consistently.
Think about it: When I ask amateurs how they managed to take that triple bogey at the fourth, the story invariably starts with, “I missed the fairway on the [left/right].” Bad scores rarely start with, “I ripped one down the middle.”