The Gold Coast have their junior academies which have grown in recent times as they've expanded to Toowoomba. The issue is that a lot of their elite talent gets poached by other clubs, namely the Broncos who sign players straight out of the Titans academy and usually the Gold Coast have to buy back the farm (eg. Arrow, Hipgrave, Whitbread, Wallace, T. Boyd). Even players like Coates and Farnworth are products of Gold Coast Rugby League.
Where they've struggled is taking those prospects and turning them into NRL players. For every AJ Brimson, Brian Kelly, Phillip Sami, Moeaki Fotuaika etc. there's been a bunch of prospects with bright prospects who just plateud in the 20s. A couple of them like Jahrome Hughes and Hymel Hunt were fortunate to find better fortune elsewhere but it's been their development pathways that's hurt them.
Eastern Suburbs have one of the smallest (if not the?) junior catchments in the game. They do extremely well to identify promising juniors from other regions and bringing them through their own systems where they become quality players. Even in some cases like Angus Crichton, he was originally signed out of Scots College by the Roosters before Souths poached him out of the Roosters gun 2014 SG Ball side. There's a lot of stories like that between Sydney and Souths where one side will go into the other catchment since they're so close to one another.