It is kind of shocking how many can't look past that high school ranking when forming their opinion on a player. Or those that will get hung up on a few percentage points, like somehow there is this massive difference between a .910 - 4* and a .880 - 3*
The recruiting sites have a formula, and they get it right a lot. But it is impossible to accurately compare the abilities of players across the country going up against different levels of competition and playing in different systems. Now it is probably a bit easier in basketball because the top guys go head to head a lot in AAU but even there, once you get beyond the best of the best they are just guessing in a lot of cases based on what has happened with similar athletes in the past.