Betts, JBJ, Beni, Barnes,Vazquez and Swihart were all drafted by the Sox. International draft yielded Xander and Devers. JD, Price, Moreland and Brasier were all free agent signings. The rest came by way of trades, Sale, Pom, Pearce, Kinsler, Eovaldi, Hembree, Holt, Kimbrel, Porcello, Kelly, Nunez, E Rod and Sandy.
You can argue that trades were made possible by having a strong farm system. We just seem to struggle developing starting pitchers.