I have a friend who is a mid-level manager at one of the listed companies, who came in without a degree, and was promoted because of proven competence to where he is now, and is spending several hours a week working on his degree because he's been promoted to the point, none of his superiors will let him be promoted further without a degree, despite handling the job better than his peers.
On the flip side, I've worked with people with a degree in CS (or similar), who couldn't develop a good software system if their life depended on it. The other side of this is, that many people don't continue to learn and only stagnate once they become familiar with one system. Software development tools don't stop coming out... there will always be new languages and platforms, but I have always seen a lot of resistance... I'm one of the few 40+ y.o. developers I know who keeps an eye on what's coming up in the community.