The league is actually pretty good at picking out the older players who have what it takes to succeed. Guys like Desmond Bane, Derrick White, Cam Johnson, Payton Pritchard, Jaime Jaquez, these weren't the biggest most glittering stars in college basketball, but NBA scouts saw the ability to be major NBA contributors and took them in the first round. But contributors, not superstars.
And then there's reaching for a senior coming off a superstar NCAA tournament win like Ochai Agbaji and he's a total nothing.