According to Dan Sullivan, Babs Smith, and Michel Néray
Focus on your strengths and delegate your weaknesses
Frank Sinatra does not move pianos. Frank Sinatra sings.
But before the days of electronic pitch correction, he couldn’t delegate not singing flat.
It’s good advice to delegate your weaknesses. But if a weakness can’t be delegated, it might be worth working on it at least a bit, even while keeping the main focus on strengths.