People who judge themselves by external metrics and think higher must be better can become overachievers, but getting depressed about their “failings” is just as problematic. I don’t mean this as a happy go lucky, showing up is worth a prize. I mean it in terms of the evolutionary pressure, body builders make poor marathon athletes.
The rank for strongest person goes in one direction, the rank for weakest person goes the other. To say your behind suggests a preferred and ranked ordering, that’s reasonably true of checkout lines at the grocery store. However it’s not so for total body weight as neither 50lbs nor 500lbs is the ideal adult body weight.
It literally says not to compete with others. If you still see everything as a competition, you're not taking the advice.
And if you're competing on an absurd metric that nobody else even thinks is a competition, like being the heaviest, then you probably have other issues that you need to work on.
Some things like being able to clearly communicate in writing or even just walking are inherently useful. However, if the benchmark is being able to walk that’s pass fail, what does it matter if your in the 15th percentile or 90th percentile walker? Similarly not everything makes the cut. Judging a RPG wizard by their strength score misses the point.
When someone accepts that splitting their focus isn’t free. Then not learning French and not being on the top 10% of something was also useful. Judging yourself by external rankings in multiple categories is therefore foolish. Having a higher rank in something may be counter productive.