Part of me wonders whether trying to optimise at all is the problem.

The worst managers I've had were optimisers (and had the worst teams), and the best managers with the best teams weren't optimisers.

The best ones didn't care about metrics at all, but would work to get their teams the tools and/or conditions they wanted to do a good job. Of course it probably only works with a certain level of talent and alignment in the team

There's also the executive's incentives, and "I'll be gone, you'll be gone": the payoff for that is very long, and it will be hard for them to take credit, and their own tenure might not be as long as that team's.