Well, yes. Stitching and pixel binning will certainly get you there.
If you have a sufficiently nice full format sensor you can open up a couple stops from wherever you'd shoot with the Phase ONE, and crop it square or 6:7, and virtually nobody (and possibly absolutely nobody) is going to be able to tell in blind testing, unless you print big enough that the raw pixel count will tip your hand. But you can't always open up a couple of stops, etc.
I get that MF is a different thing. I know that. It just seems that for almost all the cases I can think up, I can replace a $48,000 camera with a $1000 camera and a very modest extra effort. What I'm curious about is specific use cases in which that won't work, or in which the extra effort isn't pretty modest.
I would think that would be when you want the best possible single-shot application: for example, shooting fashion models who are in motion, not necessarily for magazines, but for the actual clothing stores. Go look at the photos in a Victoria's Secret store sometime -- creamy complexions on photos that are 9-10 feet (three meters) tall. These are not rare shots, either; if you walk through Manhattan, you'll see something like them in most stores -- thousands and thousands of large individual fashion shots. There are also landscape applications for things like this -- not a static landscape, but perhaps one of those flower shots as in the Arup Biswas article (the cover shot for the article.) The problem there is if you are planning to print large to put the photo over somebody's couch, as a piece of art, you may have to go six feet (two meters) wide and the flowers, in even the lightest wind, won't hold still for stitching shots. And with a shot like that, with somebody maneuvering a light modifier just out of camera view, you could shoot a couple hundred shots to get a perfect one. There are some serious uses for single-shot, high-resolution cameras. That doesn't mean that everybody needs one. They're specialized instruments, and if you take one out to shoot street in the wrong neighborhood, you could find the camera stuck where the sun don't shine. Because of the shooting I do, I'll stay with a Panasonic GX7 and a nice discreet zoom; not many people are gonna want one of my shots over their couch, anyway, and I have no desire at all, or need, for one of these things. But some people need them.
As far as price goes, it's no more than a lot of cars, and if you use it to make a living, and can deduct the cost, the price doesn't look quite so formidable.
