My axle doesn't rotate. The wheels have bearings in the center so all the friction/heat is on the sealed bearings.
Now, I have replacement pneumatic wheels from Tractor Supply. The original wheels did have the plastic of the wheels rotate on the non-moving axle.
Second point - I use a bungee cord to make sure the handle doesn't come off the ball as easily. I also usually have the DW pull the tote while I walk behind it to make sure to catch it if the handle comes off. And I need the exercise, and to make sure she keeps the speed down.