Every invention is considered magical thinking by some until it is made possible. Nothing I noted is actually magical or prohibited.
As for its feasibility, that's an engineering task. No cooperation is necessary from workers. It is in fact much more feasible than developing a modern LLM.
As for its cost, various optimizations are possible as with LLMs. Also, there are high costs to incorrect classifications currently made by management, so high that they can result in the disposal of the firm.
Please, your employer captures everything you produce for your work. They have your screenshots, emails, chats, git history, Zoom call transcripts, and everything else. You signed off on it too. So save me the "this is ethical" crap. Actually it is ethical because it is much closer to being a blind and unbiased way of gauging utility.
This is only possible because they broke the power of labor unions. Nothing you've said convinces me that it would be unbiased or even measuring something real, in which case totally arbitrary decisions made by machine would be denying people access to basic necessities under our economic system.
As for its feasibility, that's an engineering task. No cooperation is necessary from workers. It is in fact much more feasible than developing a modern LLM.
As for its cost, various optimizations are possible as with LLMs. Also, there are high costs to incorrect classifications currently made by management, so high that they can result in the disposal of the firm.