Agreed - if I were evil, I would use this data to look for long periods of static/unchanging desktop screenshots to look for inactivity and employees lying about being there or away.
Honestly this is just an arms race. If the above happens (and if I can come up with that use case think about what will come up when someone actually smart thinks about it.)
The response? I’d make a tool that presses alt-tab every 15 seconds a random number of times - to both keep the computer alive and change the desktop view, maybe move the windows around a bit for variety. A usb rubber ducky would be perfect for this.