If you sort this table by minutes -- that is, minutes played in UEFA Champions League by nationality -- you see just how far the U.S. still has to go to compete with the traditional powers. https://twitter.com/sean_forman/status/1303898525076512774
The U.S. ranked 43rd in the world in 2019-20 with 796 CL minutes. It's likely this number will double in just the group stage if Pulisic, McKennie, Adams, Reyna and Dest stay healthy and don't get benched. If all that happens, we'd be ranked about 28th. But...
...the Brazilian player pool (#1 in the world by this metric) logged 23,028 mins in the last CL. France and Spain also broke 20k. If we're realistic, it's unlikely the U.S. will crack the top 20 this season. As @sean_forman said, we need 3x or 4x as many players at this level.