I wouldn't say talent is the only way they got in, but I would admit that it's a big part of the equation for top level players.
Natural talent still has to be trained and honed to be of any use at that level. The guy with the talent may be badass on the sandlot, but when 'all' the players are pretty equal (except for the superstars) then it's a game and a matter of who wants it more (and can execute).
Even the superstars are dealing with physical issues, sometimes more than everyone else. Playing with pain, they all want the ring. (...and then the cash, the bling, the crib, the cars...)