If you actually think that something bad is going on, talking up actual hierarchy (complaining to higher ups) or leaving are only two sensible options. And if complaining to higher ups, then you put your resignation to HR.
But none of my interactions with HR made me think that these would be people capable to solve issues. They don't have processes to even realize problems are happening. They don't have trust of employees either.
I've interacted with HR teams at a couple of jobs in the UK. These interactions have been fine. They have been there as the contact people to make sure I get paid for my work, that I can access my benefits, and that I am subject to the procedures and processes that I'm entitled to.
They are paid by the company and therefore they of course work for the company – and part of that job is ensuring compliance. But this is the same as e.g. a security officer, or a health and safety officer, or any number of other roles the involve running companies correctly and in accordance with best practices in a way that can benefit both company and staff. It's not an "either-or" situation!
I would see this as "routine administration". It is useful thing.
> with suggested lines of questioning for soft-skills, a framework for the decision process
Our HR quite sux in these. They also consistently attempt to match people on positions that don't suit them - both by personality (the persons personality not matching job) and by technical knowledge/background. So their input is not trusted and managers doing hiring consistently complain about it or simply ignore them.