According to a source:
While NBA players are not prohibited from competing in the 3x3 Olympic event, they are required to amass 'ranking points' earnt through playing FIBA-approved 3x3 tournaments such as World Cups and stops on the FIBA 3x3 World Tour.
As a result, NBA players are unable to commit their time to these events, leading to the nations filling their teams with specialized 3x3 players.
This differs for the women's side, with select WNBA players more willing to compete in the lead-up 3x3 events, resulting in names including Rhyne Howard suiting up for the Paris tournament.
https://www.sportingnews.com/us/nba/news/nba-players-olympic-3x3-basketball-paris-2024/9747799b8e7a7546c8b7403d