The advantage for the end user with a folding bike is that it comes completely assembled. Unpack it and unfold it and it is ready to ride. The disadvantage with the majority of e-bikes, folding and non folding ones, is their weight. I had bought two folding e-bikes that were Class II and had great range and power but each had 4" wide tires and weighed nearly 70 lbs or 140 lbs in total. The wide tires and the weight meant only a very few special platform type hitch mounted bike racks would work. Even with the 1UP rack I had to make modifications for the fat tires and modified a motorcycles ramp to use for loading the bikes. I sold them and bought non-folding ones that each weigh 27 lbs and still will be using the 1Up rack but without the fat tire modifications.
For RV use a concern is both the weight of the bikes and how to keep them from being stolen from the rack while the RV is parked for any period of time. There are measures one can take but they are not completely effective and so we will continue to use our standard road bikes with the motorhome. These bikes are covered by our regular insurance policies whereas the new e-bikes would cost us nearly $900 a year to insure against theft.