I just went through a job search where I was thinking
a lot about this. Right now, it seems like successful startups require the founder to have some
secret knowledge
or expertise when competing with bigger companies that can just throw money at their problems.
In fact, the startups that I spoke with that were doing interesting and market-competitive things had a lot of leadership and guidance from wizened engineers and researchers - usually much older than the startup stereotype.
In the end, I think it's a startups job to shake-things-up, and approach a problem from a new angle, which is a young-man's game, but now with the calibre of thinkers working in technology, it requires some deep knowledge in a particular field. This (hopefully) comes with age.
tl;dr
Yea, I've been noticing the same thing.