Out of those three, Messi is one of the most famous players in the most popular sport in the world (that Americans don't really follow, for some reason). Lebron does something that's popular in the US, but I didn't really recognize him. Zuckerberg is well known among those who follow business news, but he has little visibility in everyday life.
If you restrict the audience to Americans, we can use this YouGov survey: https://today.yougov.com/ratings/international/fame/all-time... The most famous millennial is currently either Beyonce (#6, a borderline millennial) or Taylor Swift (#14). Zuckerberg is well behind them at #99.
If you restrict the audience to Americans, we can use this YouGov survey: https://today.yougov.com/ratings/international/fame/all-time... The most famous millennial is currently either Beyonce (#6, a borderline millennial) or Taylor Swift (#14). Zuckerberg is well behind them at #99.