Those 18-20 year olds will be
four years older by the time the next Olympics comes around, and they'll be tested under the harshest conditions to make themselves better along the way. Nobody is saying that it's promised they'll develop into players of note, just that they have the basis there to run a timeline with players who can be something to play alongside Wemby.
It's not out of the realm of reasonability that those young players, alongside some vets can't form a formidable team for the next Olympics.
They've literally made the Gold medal game for two consecutive Olympics, pushing Team USA to the brink both times, even with a noticeable talent disadvantage (so they clearly have a structure in place that is successful on the Olympics stage), yet somehow there's all this pushback about them doing something in 2028 when they'll likely have the best player at the tournament.
All that this tells me is, folks don't realize how good Wemby will become.