I see "small and simple" as a compromise, a deliberate trade-off. We give up some things to get other things in return. Obviously we can't take as much with us on trips, but once there I really enjoy taking what we do have anywhere we go.
On the trip to Maine we are on, it was great being able to follow any route we wanted -- no bridge or tunnel restrictions. While in Acadia NP we could drive to a few places where RVs were prohibited -- due to parking which wasn't an issue for a 20-ft van. Granted we could have driven there in a toad, but it's nice to have our own food, drinks, toilet, cameras, telescope, etc. with us. And if we decide to eat out while on the road we can park easily in any restaurant lot.
We also travel in rented larger RVs often and I do prefer smaller over larger. The only question is how small does small have to be to get most of the benefits. If it can't almost pass for a car, it might as well be 30-feet long.