@remi 47 here. been programming professionally since about '98.
for me, I find it's my experience that keeps me relevant. there will always be new programming languages and frameworks, but the big issues stay the same.
I've always been the "the buck stops here" guy - if an issue isn't solved by someone else, it eventually finds its way into my lap. And because it might look similar to something I saw 15 years ago, I solve it quickly. A new developer just doesn't have the xp to do that.