It strikes me as another way to make sure dark triad people get promoted and other people get crushed because being evaluated on lots of twisty little goals gives the self-promoter many ways to look good and make honest people look bad.
We structure flexibility into annual objectives so we can be flexible during the year in creating key results tailored to changing conditions.
I like ending our semester and being able to break down how much time we spent doing what, from a macro perspective.
But I've seen many teams struggling adopting OKRs, it's really hard to define reasonable long term goals for certain professions. Also, the more metric centric are your OKRs, the more issues you will have.