Younger programmers: know less, but are more flexible learning new things; broad yet shallow
Older programmers: tired of having to be "flexible" for decades; extremely deep knowledge, siloed
Most clever programmer I saw was a guy in his 40's (in early 2000). He was a layout engineer who wrote a PowerPoint+VBA design rule checker for extremely rapid prototyping of layout ideas.
Most clever team I met was a group of 30 somethings (mid-1990s) who wrote a CPU architectural simulator that was essentially a tweak of the first linux kernel.
Most "how the fuck did you do that" was a 25 year old out of Russia who wrote a Windows 10 hack for hooking system calls for performance monitoring. He did things Windows docs said you couldn't do. All un-commented assembly. Glad I left before I had to own it!