Its more than things being "hard". Its about the nature of the questions philosophers try and answer.

Kant and his Critique of Pure Reason has those 4 quadrants of "knowing". A priori vs posteriori. Synthetic vs analytic. Its literally a CRITIQUE of how far pure reason can take us. In the area much of philosophy dances in, pure reason simple cant take us very far!

[0] https://en.wikipedia.org/wiki/Analytic%E2%80%93synthetic_dis...

Finding "a" reason to live matters far more than finding "the" reason to live. Would we rather be happy or would we rather be right?

I like this quote attributed to Kant: "Rules for happiness: something to do, someone to love, and something to hope for".