Being good at poker and successful at poker are two different things.
A great player with no discipline, BR management and determination will not be as successful as a good player who does have all those qualities. This goes for away from the table just as much as on the table. Just take Stu Unger for example as he is considered of all-time but not really successful for many reasons.
The most successful players need to be able to put in work to improve game and stay at top level, practice good BR management and be determined to put in volume. This is long-term success as luck factors heavily in short-term success.
To be good at the game itself you need to have well-timed aggression, good math skills and heart to put it all-in in various situations.