Patience is a virtue with these young teams...
It took Steph and the Warriors 4 seasons to become competitive ('12-'13), after winning 23 games in the strike shortened season of '11-'12. Excellent drafting (Steph, Klay, Draymond, and, on a lesser note, Barnes) and acquisitions at the right time (Bogut-Ellis trade, Igoudala signing, not trading Klay for Love). Today, they've been to the Finals the past 3 years and their window will be open for the foreseeable future because of their patience.
Minnesota is a prime candidate for making a leap in the next few years with the right moves. Towns is an elite player in the developmental stage, but already a top 30 player. Wiggins is a top 50 player with the potential to be an elite player, and Lavine has developed ahead of schedule into a top scorer. With that core, Thibodeau, and the trade assets they have, they can accelerate their timetable for next year or 2018. Horford would be a Bogut-like acquisition once this team is ready to compete (although Boston isn't trading Horford and his value is higher than Bogut's was at the time). For a more immediate impact, how about after this season: Dieng, Rubio, 2017 1st (they're positioned to be a bottom 5 team) for John Wall?
Young teams certainly work, but patience (and intelligence) is key. It is the difference between the Warriors and OKC or Utah and SAC/NOP.