The roster construction issue is becoming all the rage. The Thinking Basketball guys did an interesting podcast on the best 3&D guys ever in the NBA (see here:
Thinking Basketball | Podcast on Spotify ) and at the end of the podcast (around the 72 minute mark), they made the point (that everyone else here is making) that USA BBall would be much better if they replaced several of the high load (or high usage), ball dominant guys with 3&D guys like OG, KCP, peak Danny Green, etc.
Karalis also discussed this on the podcast and made the point that one way to make up a talent deficit, is to spread the more talented team out and see if the 3P shot can be the great equalizer. Which S. Sudan (14-33 versus 7-28, or a 21 point differential on 3Ps) and Germany (13-45 versus 6-17, also a 21 point differential) almost did.
Team USA is getting out-mathed, and the problem is that either because they aren't used to the system / don't have enough movement on offense given that most of these guys aren't used to moving off-the-ball / just see a mismatch in front of them every time they touch the ball, they aren't getting enough 3P looks.