For those concerned about "Earth Ground"... It is Chassis Ground we need to be concerned with INSIDE the RV, earth OUTSIDE. But let me explain again why it is improtant WHEN ON SHORE POWER.
SHORE POWER has an earth ground, in fact several of them in many places.. For sure there is one at the service distribution panel, may be one at the transformer. I see them at many parks at every outlet box.
At home you have one, the pole has one, your neighbor has one.
At one time in my house I had a bad neutral lead on the drop from the pole,, I also had a bad earth ground (one of the two) so I had voltage swings when the Air Conditioner or other big items kicked in.. Power company diagnoser came out and fixed the bad ground.. Drop crew replaced the drop (later).
IN this set up if you manage to come into a hot wire (or a tool shorts to case,, As HAS HAPPENED TO ME, you become the alternate return path, not so much to ground as to neutral (Via ground).
INSIDE the motor home running on inverter or generator.
IF the Genny or Inverter is using floating neutral. Then there is no alternate path to ground, Earth or Chassis.
If its bonded, No alternate path to EARTH due to the rubber tires, assuming they are the only thing in contact with ground, but.. You still have Chassis ground.
So the GFCI remains important to your safety.
Home is where I park it!