There's really no reason for that camper app to load so slowly. Rendering the initial screen then loading additional assets in the background with a prioritized queue could probably cut the load time by 90%.
Well, no. Of course not. It's not at all about the technical feasibility, or even the ease, of delivering content up front. The web first began with the ability to deliver content up front and it's remained a viable option all long.
The continuing problem is that people (CEOs, designers, developers, et al) get sidetracked and forget what their site is supposed to be doing. They forget what their customers or prospective customers actually want to do: get information; use a service; buy stuff.