Of course no singular stat is the be-all end-all. There are examples in this thread of "I can't hit a headshot but all I do is win" - and that's great... like, if you can't hit a headshot consistently (like me), going for it every time will just get you killed because your aim isn't good enough, and you will lose more in the short term as a result.

In the long term though... imagine if you play against somebody who is roughly as good as you, roughly as smart as you - but they can hit their headshots more frequently and reliably. In the long run, they will dominate you. That's how I see it. I can get by without headshots, but I should aspire to hit them because it's an important aspect of my game I need to work on, the same as I should work on movement, shotcalling, smoking, whatever else.