Let's start out with three observations: the first, that academia has become a highly professionalized system to generate the appearance of important results, frequently at outrageous cost, and usually diminishing the importance of actual work that can be done. Every field has become marginalized, in that no meaningful leaps forward can occur. There isn't space for it – if you don't publish something quite frequently, you'll be fired, and even practical application is secondary to polishing whatever you can push out of the door. There are people who exist solely to help people write grant applications, other people who solely review grant applications, and no good reason to think the system does any better than randomly choosing among the plausibly OK proposals. And doing work without a clear direction or knowledge of what you might want to find? Well, there's no room for that at all. A good primer on this phenomenon is the bone-chilling 'Could Einstein Get Published Today?' article at The WSJ.
The second is that university education is both essentially mandatory for many fields of white collar work, while not specifically preparing anyone for their roles. If you don't have a degree, it can be a bit of an uphill climb (until, of course, the inevitable preference cascade, after which you will seem to be an utter fool for having spent so much time and money on something of no value). Yet it doesn't teach you how to actually do any specific job, and success and failure within the university system is largely unrelated to and distinct from your success in any particular field.
The third is that universities are now essentially luxury spas with optional binge drinking and on-site lecture events. Instead of a barracks within which young adults are warehoused as efficiently as possible to achieve their scholastic goals, college campuses are now routinely so luxurious that I never was able to return to that level of indulgence afterwards, not even after making six figures. It's not just that it's wasteful – it's that it's plausibly why young people might say it's the best years of their life. There are parties, socialization, specific expectations you can readily meet. It's the same constrained, low-stakes, clear-visibility environment of a video game, but happening in real life.
But college wasn't the best time of my life, as much as you might hear things like that. My parents said it might be the easiest way for me to find someone I could marry – otherwise I might not have gone, and I certainly prepared other specific plans – and I didn't find that. It's not an environment where many people are prepared to take the world seriously. I strongly recommend every student have at least one close friend in their university experience who is an actual adult, there because they need the degree. People who made a choice. Otherwise the whole experience is so ungrounded that you're unlikely to find any happiness at all.
The whole system has had waning significance to the broader American experience, but soaking up more and more resources. I firmly believe the marginal value of college is negative for society, and is pushed forward because it can be slightly positive for individuals.
Faculty are producing few results that I think are meaningful, and they would be better off starting a business, almost no matter which business it is. A pizza shop, or a laundromat, for instance, might be a better marginal use of their life than academia. Colin Percival clearly believes this is the case, and he is more suited to academia than almost anyone. I see no flaw in his perception of the world, and I trust his wisdom. He's made more interesting new things than me (if not in literal number, than clearly in interesting-ness).
I will leave you with a simple thought about the currency of modern academia: the citation. I do not commonly use them on this site. I do not commonly follow citations in things I read. I sometimes google things to find the truth of an issue from scratch. Citations aren't useful to almost any readers who care about truth instead of justification. They're maximally useful to students who wish to use e.g. Wikipedia without looking silly to people who think they ought to not cite Wikipedia. You look up citations, use the same sources as someone else, and do the same analysis someone else did. Thereby, citations are a tool for homogeneous analysis and thought, and actively retard organic understanding, novel analysis, curiousity and scholarship, in almost all cases. Einstein didn't use them in his paper about General Relativity, and there was plenty of previous work he could have cited. So when something that is frequently meaningless and often harmful to scholarship is used as the token of achievement, what culture would form? Who achieves in that system? And what would they miss?