The Red Sox seem to constantly be bringing All Star caliber players up from their minor leagues. They're one of the organizations I most envy for being able to consistently produce productive MLB players without having to enter a rebuilding phase, alongside the Cardinals. Red Sox fans complaining about trading prospects seems decadent to me.
yes and no. Cherington held onto prospects perhaps too tightly, but since Dombo, the depth of the system has been tapped out. Chavis was a 'roid busted power corner infielder who was I think a low 100s guy. After an initial hot month, he's back down to Earth. Devers and Benintendi came up a 3 years ago initially, I think. Turner, Soto, and Robles are hands down better. They've come up with no valuable pitchers, so I'm not sure they have better development than the Rays. As for Toronto, it's early, but they seem to have incredible talent.
The big prospect for player that'll put you over the top moves were the Kimbrel and Sale trades. The cost was Moncada, Kopech, Assuaje, Margot, and I forget what other pieces. They traded their best pitching prospect in years for Pomeranz (the kid ended hurting his arm but is still high in the SD organization). They moved Shaw and some other good pieces for Thornburg (easily his worst trade). I forget some of his other prospect dumps, but the system is just not as productive as when it had Bradley, Betts, Bogaerts etc... in it, plus the ones I named, plus Chavis I think in low minors, etc...