While cash seems safe, it is steadily losing value. In addition, the constant forces of inflation will erode wealth stored in cash over time.
The Dead Sea is fed by the Jordan River but has no outflows. So it continually gets saltier, and nothing lives in it. Focusing too much on saving can create a similar toxic mentality.
It is not just about amassing a huge amount of savings so you can retire. By investing in growth, you are actively putting money back out into the world.