In a few words, is to get better, perform better, live better, happier.

Is it that needed? no cause people can live fine performing worse, living worse, and living less happy, etc.

In the end most of the times it makes sense cause it makes economic sense, spend x money+x time to perform better the rest of the years is cost effective.

Like running with deflated tires, sure you can run with deflated tires fine for years until the car goes bust but inflating them takes so little time and is cheap.

Or living your entire life without shoes, shoes are not needed but you perform better with them.