The impact of a lie angle that is 1° too upright could be an #8 iron approach going 4 metres further left of the target than it should have. That could be off the green, or in the bunker, or even in the water. The only fault of yours was that your clubs aren't properly fitted for your game. Perhaps you had them fitted to you a long time ago or perhaps you've never been fitted.
Just when you enter the scoring zone, the impact gets worse
Take a #5 Iron out of your bag and raise the toe slightly making the club a little too upright, and then imagine the line of the ball coming off the face. It’s going left. Now take a higher lofted club, an #8 Iron, and do the same test and you’ll notice the impact, or amount that the ball is going to go left, will increase.