I have given this some more thought and my theory is that probably most of the currently young devs will turn into old developers that will have stooped learning a long time ago. I guess that's the natural progression of things. Most people stop learning at some time. It happened to people who started 30 years ago and it will happen to the currently young hotshots too.
As an over-50 programmer who likes to learn, I'm gonna talk about something totally unrelated to programming...
I'm a musician. I've been playing guitar since I was a teenager. As a technician, I've peaked out. I will probably never play faster, cleaner, or more complex than I do now. If anything, I'll start to go downhill as age takes its toll on my hands. But as a musician, I'm always getting better. I'm growing more conscious, more sensitive, more subtle, more sophisticated. I'm a better musician now than I was a year ago, and a far better musician than I was five years ago.
There's a similar thing in software. When you're still learning, still approaching real expertise, it's easy to think that being a great software engineer is about technique. It's not. I know a bunch of over-50 programmers. Sure, many are basically dead in the water, but many are not, and are constantly improving. It's not because they learn a new language, or a new framework. It's because they learn better taste. They learn more and more what is and is not important, how long things will take, best use of resources, translating requirements more effectively... these things will all make you a better engineer than writing glorified Hello Worlds in framework-of-the-month ever will.