There is an element of chance to all this as well. You can do everything right and some guys just won't develop, and sometimes you get more than you should.
To an extent we got lucky that all of Bogaerts, Betts, and JBJ panned out. With honorable mentions to Vasquez, Shaw, and Barnes, I also wouldn't close the book yet on Swihart and Owens. But one thing to consider when evaluating the narrative that we haven't been able to develop pitching in a while is we have not had a blue chip pitching prospect in our system that was the equivalent to a position player prospect like Bogaerts and Betts. Also, high end, cost controlled pitching is the rarest commodity in baseball. Throw in a hint of luck/chance and the Sox aren't exactly in an unfamiliar position. A lot of teams have had these issues as well. I think prospects like Espinoza and Groome are different than the pitching prospects they've had in the past, which ultimately still doesn't guarantee success but conversely the past shouldn't be an excuse to just trade all these guys away. I think Kopech is kind of in-between, I don't think he's the same guy as Espinoza and Groome but he might be a step up from the prospects we've had in the past from Barnes to Owens.