Multiple countries are using this Worlds to give opportunities to other gymnasts, not just their very best.
Alice D'Amato and Manila Esposito are being rested and the focus is on the younger athletes and building depth. Both gymnasts could have won multiple medals here and IMO Esposito was the favorite for AA gold.
You don't really know the rationale for each federation's selection.
If fielding a full team to Los Angeles is the federation goal, giving an opportunity to younger talent in need of experience might be the route to take, especially when there is no team event.