People need a belief system to understand the world around them, their role within it, and the way(s) in which their future can be better than their present.
You can always find a reason to complain, and you can always find a reason to be grateful. The former will lead to a miserable life; the latter will lead to a more pleasant life.
https://yourmeaninginlife.com/blog/it-will-always-be-something
There are many misconceptions about how important growth is to your life, from what kinds of growth are possible, whose growth is meaningful, and how growth is meaningful even in the face of endings and death.
https://yourmeaninginlife.com/blog/misconceptions-about-growth-oriented-meaning