The rest of the world is too good at basketball for the US to breeze through with their C team. Coordinated team defense is a requirement instead of the typical playground ball that used to work. Unfortunately the top American players will probably sit out next year to avoid wear/tear on aging bodies (Lebron, Steph, Lillard) or avoid injury for injury prone players (Durant, AD, Kawhi)
In both losses, Austin Reaves got hunted on defense. Can hardly blame him as last season he was a 2nd year role player, now expected to be a major contributor. He seemed to be one of few players who actually cared
The US' 3 big men were Jaren Jackson Jr (not an offensive threat), Paolo Banchero (SF in a PF's body), and Bobby Portis (oh.)
No surprise they got eaten alive. Kessler is raw but he was needed, didn't get minutes for some reason
Haliburton, Bridges, and Brunson have just started to be the main guy on their teams, so they weren't experienced enough to translate it internationally. Josh Hart and Cam Johnson are great role players in the NBA, but that didn't translate either
Ant Edwards is going to be a superstar next season.
Realistically who will the US bring out next year? There are some really skilled G/F players (Booker, Tatum, Beal, Trae) but the NBA is lacking superstar American big men other than AD, who probably won't play