Ones with tallent are still developing. How many great PR players were in the league at any one time before they were lumped in the draft? Next year there will be Yadier Molina, Carlos Correa, Francisco Lindor, Javier Baez, along with a dozen more.
The difference in the number of PR players that have debut hasn't changed much between now and then. Maybe a couple players a year. And that could be because there are more players coming in from other places taking their place, like Canada and Southeast Asia.