Stopping every 2 hours might be the norm in Europe, but in the American West you can drive 8+ hours and not even hit another city. If I jump in the car and head west right now, the first city of any size I hit is Reno, Nevada (which isn't exactly a big city). It's 7.5 hours away. The first major city I hit will be Sacramento, CA at 9 hours and 40 minutes.
Heading east will take me nearly 8 hours to reach Denver. Las Vegas is practically in my back yard thanks to 80 mph speed limits, I can get there in only 6 hours (it used to be our lunch stop on the way to LA, back when we got fuel there).
Going north - well, there really aren't any major cities in that direction since we just have Wyoming, Idaho, and Montana up there. But let's take Boise, ID as the next good-size stopping point at 5 hours away.
Out here in the West we have to put the miles down. This is one of the reasons American cars have historically been large and comfortable; we spend a lot of time in them for long stretches. Honestly, if I didn't have to stop for fuel, I would probably drive all the way to Barstow before pulling over. My coffee mug keeps my caffeine delivery liquid hot for 6+ hours, pack a sandwich and some snacks, keep a bottle of water nearby and power through. I would regularly drive solo from the Bay Area to my parents' house stopping only for fuel (and to take a leak during that stop). It's a 10 hour and 30 minute drive without stops - and I did it without cruise control.