There is zero benefit to bringing up players before they are ready. In addition to the obvious possible stunting of development and losing baseball, you dont even save money. Player X’s salary structure is pretty much the same whether their rookie season is at 19 or 24. There are three years of serfdom, followed by three years of arbitration. The only question is, when do you start the clock? And by pushing off their rookie season, you actually stand a chance of getting them cheaply through their prime, rather than paying them to learn, and then watching them hit free agency at 27 or 28. Minor leaguers should always have to force their way into a big league lineup. Always.