I don't have any statistics to back this up, but I would guess that in many (most?) fields that don't absolutely require degrees for legal/other reasons, someone who spends 4 years actually working in their field is going to be in at least as good of shape as someone who spent those 4 years getting a degree (and maybe even better, depending on the field).

That said, getting that first job without the degree is the hard part—connections and luck play a huge role here. Everything after that becomes substantially easier, and the benefit of a degree becomes lower.