But there is a fix, provided by TinyMachines (https://tinymachines3d.com/products/creality-10s-pro-extruder-lever-exchange-program). They will mill out the lever and provide some bronze washers for $12.50 (plus shipping). It is cheaper to get a new dual gear extruder from Amazon, but it looks like many of those will probably have the same trouble in time, so this is a better fix if the idea is to keep it stock. There are certainly better options for direct drive extruders, but right now I just want it working again and don't have the time to spend installing a Bondtech of Titan (which require firmware and vref changes). Not sure what the turnaround time is on it though.
And here's a great video which explains the fix from Liqui-Dirt 3D.
The extruder arm will still get replaced once I get the fixed one from Tinymachines since I can see definite wear on mine (and the gear can now move a bit over a mm up and down in the arm due to the problem), but the worn arm does not seem to be the problem in this case.