Proof is living here in India. Watching year after year, your seniors, neighbors, cousins, class mates, tuition mates, office colleagues burn through insane hours entirety of the whole academic life from childhood till late teenage, working for doing good in exams, scoring the top ranks that there are, and yet being denied seats in professional colleges.
The very fact that you ask for proof means you are completely disconnected from the everyday reality of life middle class hard working students face in India every single academic year.
Even today I meet freshers at IT companies who have stories of having scored in upwards of 95% aggregate marks, and best rank in competitive exams(JEE, NEET, NATA, CET etc) and lose out an engineering seat to some one who had 35-45% marks.