not a whole line like that, but there are some situations where you'd want two of them spaced that way and it doesn't really make sense to put a belt or chest in between them. I'd assume the image was mostly just to illustrate that that layout could be disrupted with a ghost.

Only reason I have is if you're doing a no-belts run.

burner-inserter loops aren't a bad way to dispose of wooden power poles after refactoring your early base. I usually just set up a logistics chest to request some and then feed them into the burner inserter loop.

You're out of belts.