Skill is good and educational certificate is also good. Having any of them can actually put food on your table, but the question is which of them will you let go for the other. I mean education can get you a white collar job the same way a skill can too. For me i will let go of the skill because skill without basic education is not good at all. Because I have seen a situation whereby a guy with good skill who got a job was unable to give quotation and he lost the job .Formal education is good for everyone.
Actually, the usefulness of a document confirming education is obvious. But the skill is also very useful. After all, the employer needs a result from you, regardless of your formal education. I have seen many specialists whose hands grew out of their asses, but at the same time they had diplomas of education, certificates, and licenses...