i wouldn't say that there is not competition in pro wrestling. obviously there is no compition when it comes to the title shots but these guys have to compete against one another to win over fans by developing their character, their moves, being good in the ring, making it believable. the more they win over the fans the more time in the ring they get and the better their career becomes.
the wrestling companies can try all day long to try and give someone a push and the crowd will just not buy it and that happens all the time. it's really up to that individual to compete against their fellow wreslters to try and be better than another one and develope their character so the audience will buy it.