It's not that hard to get on the "30 under 30" list assuming you have the right comms advisor. If you've created a startup with decent revenue and raised a decent Series A, it's definetly doable. In fact, I've seen mid-careerish professionals make the list as well because they had the right network.
There are 20 categories, and each category selects around 30 people a year.
Like everything else, if you attended the right colleges (Ivies, Ivy Adjacent Privates, Public Ivies), built a strong enough network there, and worked your butt off initially you're in a good position to join that list in your late 20s.