They are the greatest single barrier to social mobility. That usually refers to mobility across generations - an indication of how immobile European societies are. Apparently Europe has abandoned all hope, that the unemployed themselves can reach university. Of all the components of modern education systems, universities limit mobility most. Stagnation is the result.
Universities are essential to the de facto political hierarchy.
A university degree does not guarantee political power, but, no degree guarantees no power. For all the failures of European elites, universities are partly to blame. For most members of the elite, the university has partly determined their vision of society. Universities are bad for students, even for those who succeed. If students are subjected to a series of examinations, to determine their life, then they will begin to see life in this way.