Sometimes the process is the objective. Put another way, some goals are only achieved by not reaching a terminus.
But that aside, there's an even more important point:
> I would ask you: when you judged your progress from yesterday, was it with a mat - a brutally objective test
There is no such thing.
Even in the author's example of wrestling, their conclusion is incorrect (or at least, not supported by the data they have). Their circuit could have been far above the national average in participant skill, so losing there and concluding "I'm not skilled" is an assessment based on where they subjectively drew their line of comparison.
And given that they never actually gained their supposed "heart" they believe they needed, how do they even know that would have changed anything? They could have fixed their attitude and still always lost!
Anyone who works in IT knows that metrics and measures are anything but objective truth.
Sometimes I can, sometimes I can't. Sometimes I even regress a bit. But over time, I have gotten stronger.
Some people at my gym urge me to "compete" but I can't see a reason to do this. I am achieving what I set out to do, by objective measures. Why is what someone else can do in comparison at all relevant? I am stronger than some people. Maybe stronger than most people my age. But there are always going to be people stronger than me. It doesn't bother me, because my goal and motivation was never about that.