The NBA hasn’t ‘always’ been tied to college sports. As recently as LeBron, players could enter the NBA directly from high school, but now have to wait one year. And I don’t think ‘one and dones’ do all that well in the NBA.
I think for most college athletes, getting a college education is the priority, and the path to going pro works. I wouldn’t want to see the system changed for idiots like Lavar Ball. In most sports there is no requirement to go to college or wait any time before going pro - tennis, hockey, baseball, soccer all allow 16 year olds who are good enough to go pro, but rarely are teens good enough to jump from playing against other 9th graders to playing against adults with 6 years of experience. Maybe a golfer can do it (rarely) but not a football player.