I am neither old nor completely young. What I see in engineering is a huge competency discrepancy between old and young in favor of older workers by a significant margin, even if you account for the extra experience. An exception is software to a degree, but there is no guarantee either. Young people aren't stupid, it is just that the technical knowledge density is that high today that people might have neglected some basics.
Of course that isn't applicable in this example. I believe Biden more or less slipped into another candidacy because there was no real competitor within his party. But the discrepancy in competency is sometimes visible in politics too.
There were competitors, but none of them were overwhelmingly better. Each had advantages and disadvantages. In the end, Biden was the consensus, as a combination of experience and overall favorability.
If Biden had declined to run, you would have seen most of them again for primaries this year. It's hard to know who would have won. Most of the candidates that thrilled some people were deeply disliked by others.
It's rare to find a candidate who thrills everybody in the party. Barack Obama managed it, at least for his first term, where nobody really knew him and were able to project anything they wanted.
The interesting part is that Trump thrills only part of his party, while being deeply detested by others. They do, nonetheless, turn out to vote for him.
Perhaps too much stability. Our "wisdom" is often dated -- and we're really hard pressed to reconsider it precisely because we consider it so hard-earned.
