I hate chair mats. Hate them. They always crack when you use them on top of carpeting. I actually made a giant chair mat out of plywood & floor tile to overcome this inherent weakness - but even that looked like crap after a couple years.
I’m not sure if anyone else has tried this hack, but it works great. I’ve customized five plastic “moving slides” to cover the wheels on the chair. Not too pretty (I wish they made the sliders in black!), but they work great. You can’t slide the chair with your full weight in deep pile carpet, but I don’t need to move much. I just rotate the chair a lot.
You’ll need to wire the sliders to the wheels to keep them in place. I’m still looking for a more elegant solution. Cable ties didn’t work.
No more chair mats for me…