HR involvement is unavoidable at big companies; and basics like "years of experience for payband" can cause issues. They fundamentally do not understand the job, but somehow have to ensure its not a biased hiring process.

Yes, and it is kind of necessary when hiring people from outside trusted networks. HR makes sure if people are who they say they are, background checks, and so on. Years of experience and so on are crude filters and should be bypassable by the team/hiring manager if the candidate meets the requirements. I know in large companies this can become political.