From my personal experience, the reason they do it in highschool is just to charge you money.
When I was in eleventh grade every student had to do Dor Yeshorim. But then I went to Yeshiva and started shidduchim some six years later.
When I started dating my wife, Dor Yeshorim would give ANY information, because since I took the test they added two more test, so I had to take everything all over and pay more than $250 because it had to be rushed besides for the $70 that I paid when I was in highschool.
I wished there was someone to talk to, but the only one to speak to was the Russian nurse drawing blood who didn’t know much.