The problem that most of us seem to have is that we're only tracking easy things to measure. Everything valuable is difficult to measure.
Reading a book is worthless. The purpose of reading a book is to gain something (learn something, read faster, practice public speaking, etc.). That's what we should be tracking.
Also, this doesn't really apply to emotional relationships for me. Personal OKRs are basically for self improvement which helps me in reaching something I aim for future.
I explored this throughly in 2014:
https://medium.com/@duopixel/the-qualified-self-7f69c6b23623
I have not updated this post, but I did this for years without finding satisfaction, because what I had to address was judgement about myself, not the shortcomings that I perceived I had at the time.
But the exercise of trying to measure the subjective is very instructive in itself. I ignore if you counter my point from experience, if not, I encourage you to register subjective judgement. And if you already do it, I encourage you to drop it and sense how it feels.
Many paths of personal growth require you to do opposite things at different times, so you can maximize your surface of experience.