Ah, I remember back 13 years or so, when I used to say things like "getting a degree is a waste of time, it doesn't prove anything, yada yada".
Then I grew up and saw how the world actually worked.
Then I started a business and really got a clue.
Depending on the subject, a degree may or may not give you the knowledge you need to do a job (medicine, it does. Marketing, it doesn't), but it says the following to a prospective employer:
"By getting this degree, I, the job candidate, have proven that I can commit to a project over a period of several years. I have proven that I can take information supplied to me, analyse and understand it, and present my analysis and understanding in a way that can easily be understood. I have learned to express my arguments through the written form, and I have learned to communicate with my peers and my superiors. I can demonstrate long and short-term planning, and I can prove that I produce quality work to deadline. I have demonstrated that I can work on my own initiative, and adapt to feedback."
All of that, in one piece of paper. To demonstrate all of that without the piece of paper is a lot of work.
Now, that's not to say that the subject studied bears any relation to the actual job required. For example, I run a Marketing business, but am less likely to employ someone with a marketing degree and no experience, than someone with, say, an English degree and a few years working experience in a Marketing department. That is because I am familiar with the content of academic Marketing courses and they usually bear no relation to the actual discipline. They are mostly theoretical, and you simply won't get to use an Ansoff's Matrix in 99% of Marketing jobs in the real world.
But, I would be reluctant to employ someone who has no degree at all, because they would not be able to prove they are capable of commitment, working to deadlines, working within a hierarchy, communication via different media, etc. If they have 10 years experience and no degree, fine. They have proved the above through their references, portfolio and working history. But if someone comes to me and says "I'm really smart and really capable, but I just don't see the point of proving it via a degree. Give me a job!", I will be unlikely to.