Sox are going to be mostly sh$$y until they develop a good farm system. Yea, the current snapshot of the Sox' prospects is okay today (although I suspect it's more in the 15-20 range), but the farm system and infrastructure are still bottom-quartile.
When Williams took over, yes he inherited well, but the Sox also had a good farm (which he helped to build). The Sox had a good farm from 1990-2005 (arguably til 2010) and the Sox had a good team most of those years. But from 1970-1990 and 2006-present, the farm system has been mostly bad, as has been the team on the field (except for a few short pockets of success)
You just can't trade your way to improvement anymore; teams won't give up squat in young talent.