In North America absolutely correct.
Central and South America were a whole other story. The annual Treasure Fleet to bring back the bullion from the New World started in 1566, largely because the Spanish were forced to convoy by pirates and buccaneers.
Very little of the wealth it transported came from the islands. It came from Peru (mostly from Potosi, founded in 1546) and Mexico (mostly Zacatecas, founded about the same time)
Meanwhile Cuba, Hispaniola and Jamaica were largely depopulated by Spanish colonists moving to the Spanish Main, leaving Jamaica vulnerable to the English and western Hispaniola to the French.
As far as North America (North of Mexico) no one really knows what the Spanish were up to but there were Spaniards and allies all over the place ~ maybe more than 20,000 people by the mid 1600s.
As far as developing South America was concerned, Argentina was still killing off Indians to open up lands for Italian and Spanish settlers in the early 1900s. There were VAST areas totally unsettled or developed throughout all of South America. In fact, there still are empty places.
Ever check out Canada North of Winipeg? That was Chile South of Santiago ~