Coming up with a new idea, researching its feasibility, and executing on it isn't really doable with rigidly monitored metrics, because a lot of the productive work on novel things looks like thinking about things and trying things that don't work out.
As a field we have yet to find good metrics for coding performance, anyone who tells you otherwise just wants to have an excuse to fire you when they suddenly decide that you no longer serve their purposes, even if those purposes is just to have a cool social club that validates their fragile ego.
Are you implying managers don't directly contribute to a product? Because wow, you're really either horribly naive or wildly narcissistic. As a someone who managed programmers for almost 20 years, only a fraction were hands-off. Why do you think all the 10x engineers become managers? A high performing manager hits targets, ships products, and makes customers happy. If you think a hot shot programmer on a team can do this all by themselves, I don't know what to tell you. You'll have to learn the hard way.