Would be funny to have, so you can see how fast the dirt spawns to get an idea about how much each upgrade improves the speed or amount of it. It also compliments the Dust Buildup upgrade because we then can see how much dust particles can be on the ground at its maximum and with how much it increases with buying another DB upgrade.
Plus it's satisfying to see the ENTIRE FLOOR covered in dust and then you just vac it all up. Either alone or after turning the AVAs back on.