I don't know what it's like to drive a big campervan like that but I have driven a truck before. The steering wheel doesn't control the vehicle. You turn the steering wheel with all your might (it's big!) and then count to 5 (fast count) then the vehicle does something that you either wanted or didn't expect. And it bounces around at every indulation. And the brakes are spongy. And you get an education on centrifugal force in in any corner.
Incompetent to drive a campervan in that narrow road? Yeah I think all of us would fall into that category. Bad to hog the whole road? I think so, but I wasn't in that campervan's driver seat lol