I've discussed this before, but here we go:
If you look at the RSCI top 10 recruits for the one and done era, a huge percentage of them ended up in the NBA, and a large number of those guys are still playing- something close to 70% of them, if I'm remembering correctly (not going to add it up again).
If you look at the guys rated 11-25, there is a sharp, sharp drop-off in those percentages. Which makes sense. A certain number of the very best players are going to be identified early, and then remain among the best players for pretty much the rest of their careers (which are likely to be lengthy). Historically, going back at least 30 years now, you average about 20 guys per NBA draft class who last for any significant time in the league (7+ years, 500 games), and 10-12 of those who become real long-term mainstays, playing well over a decade, into their 30's. Usually at least 3-4 of those guys were identified as potential stars in HS. Sometimes more, rarely less.
Examples- the really strong draft of 1996. You had 14 guys from that draft end up playing 800 or more games. 6 of them were definite top 10 level recruits (Kobe, Iverson, Jermaine O'Neal. Antoine Walker, Shareef Abdur-Rahim, and Stephon Marbury).
Or 2004, another strong draft, where you're likely going to end up with 14 guys hitting 800 games (careers in progress). 5 of them were definite top 10 recruits (Dwight Howard, Josh Smith, JR Smith, Luol Deng, and Al Jefferson).
Those are the type of talents you want. Yeah, there's not always a difference between a top 10 guy and a guy rated 11-25, and yeah, the slightly lower guy sometimes ends up being Devin Booker (or James Harden, or Blake Griffin), but you go for the surer thing. John Wall, DeMarcus Cousins, Brandon Knight, Anthony Davis, MKG, Nerlens Noel, Julius Randle, Karl Towns, Trey Lyles, and Jamal Murray (eventually)- all top 10 recruits.