I agree that a lot of the time intellectual pursuits are misdirected ways of solving life's problems (though the worst culprit here is wealth acquisition, doubling the critique of pg here).
There is a kind of wisdom that arises through knowledge of oneself and other people that comes with age. A kind of knowledge which helps you predict what is going to be worthwhile, etc.
However we shouldnt fall into the trap of saying "academic persuits might leave you unsatisfied therefore you can be blase about them whilst discussing them". You cant dispense with the particulars of physics when discussing gravity because your interest in "the universe" owes to a unfulfilled religious need.
"age" is a different category of knowledge and doesnt excuse or justify glorified amateurism in another.
Well, most of the stuff guys "under 40" think they know about "Metaphysics, Quantum Field Theory or Abstract Expressionism" are a half-understood mismash too (I'm not talking about someone with a PhD in Physics here).
And, as some they will find out later in life, not only knowledge of those "serious academic topics" doesn't matter as much as they thought, but also most of them are inherently bullshit too.