The book explains how Andy Grove introduced the practice at Intel and it was very effective. The book seems to attribute the success to the practice itself and seems to say "if you adopt OKRs, you will succeed like Intel did".
I suspect that this success is misattributed. I suspect that Andy Grove was probably an excellent manager and I think he could have succeeded with something other than OKRs. I think he understood that what was really important was to get everybody across the organization to focus on essentially one big goal. He needed to make sure that everybody was pulling in the same direction and together, and OKRs provided a tool to do that.
When my organization decided to implement OKRs, my question to my peers was "who is our Andy Grove?"
If the people implementing OKRs focus too much on the practice and not enough on the motivation, I think you just end up with cargo-culting. The setting and tracking of KRs becomes the objective. So people treat it like busywork because OKRs don't really seem to matter - they just gets in the way of the "important" stuff.
As one of my coworkers says, the title of the book is "Measure What Matters", but it's too easy to slide into "What Is Measured Is What Matters".