University is necessary. It is necessary as an institution because of the value that it brings to students, and through them to society. The education it provides is necessary for young people because of the discipline and structure that a university provides for intellectual development. This provides the strong foundation on which their future contributions to society are built.
Some of my readers are already chewing on what they imagine my arguments will be, searching for a single counter example. These are easy to find: Bill Gates. But of course Gates did go to college; he simply did not graduate. Michael Dell. Oops, same story. Andrew Carnegie! Never went to college at all. Success! University is not necessary! (And if you accept this argument, then university is exactly right for you.)
Of course Andrew Carnegie did endow a college, which is now a rather good place called Carnegie Mellon University. If university is not necessary, why did he do such a thing? Because Carnegie recognized the importance of education, as do Gates, and Dell. All three have supported higher education broadly, with significant sums. It is not useful to draw conclusions about the value of higher education from successful entrepreneurs like these. Carnegie was a singularity, as are Gates and Dell. They are not like everybody else: they were lucky, especially in their timing, they were wicked smart, they were hugely ambitious and driven, and they were not typical.