PETG grinding with direct drive extruder
This does sound a lot like you are experiencing the effects of heat creep (How is heat creep characterized?). You should lower the temperature of the hotend and increase the printing speed and retraction speed and possibly lower the retraction length.

If this is heat creep, a new extruder will not help you until you solve the heat creep first. A new hotend that can be cooled better might be a better solution.