It's a stupid tool and I'll tell you why. It provides no nuance or context. If you have two employees, let's say developers, and one is high performing and efficient. The other has medium knowledge but is inefficient as heck. Employee A gets the project done in two hours. Then spends the next 6 hours helping someone else. Employee B works on the same project for 8 hours and doesn't get it done.
Employee B has a lot more keystrokes than Employee A for the 8 hour period. The monitoring software says employee B is "working harder".
Are you going to fire your top performer (A) and reward your mediocre employee (B)?
This is what managers or for. Scouring these reports for some kind of usable data is an exercise in futility. It would only be employees by a leader with zero people skills and the personality of a grapefruit.