I think that this boils down to the quality of the processes inside the company:
If your *workflow* is correct - effectiveness is inevitable. You will see improvement very fast.
For example, if you set up "time to code" and the focus is there, but your devs are working on the wrong task, or an ill-defined one, you won't find the efficiency you're looking for. On the other hand, if your workflow guarantees that your tasks are well defined, and that you code the right solution, you are already 90% there.
I think that this boils down to the quality of the processes inside the company:
If your *workflow* is correct - effectiveness is inevitable. You will see improvement very fast.
For example, if you set up "time to code" and the focus is there, but your devs are working on the wrong task, or an ill-defined one, you won't find the efficiency you're looking for. On the other hand, if your workflow guarantees that your tasks are well defined, and that you code the right solution, you are already 90% there.
Tools like Fine are trying to take this approach today: https://www.fine.dev/
Full disclosure: I work at Fine.