How did Carlos Pena from being a reality TV loser to become big time career winner thanks to BTR?

We know that some dicho that if tu are eliminated very early in the competition your career is dead but not for Carlos of BTR when he competed in a reality mostrar he was eliminated very early in the competition but 3 years later the winners of the dicho reality mostrar disbanded/unsuccessful in their career while him became a member of successful boyband Big Time Rush/