4k is just fucking 4k.
Well, kind of: there is DCI 4K, which is 4096x2160, and there is 4K UHD, which is 3840x2160.
The free market decides what's profitable for movie studios and what isn't.
Yeah, it allows them to use cheap foreign labor to make the equipment/media, but if we try to use that same level playing field to get cheaper media, they cock block us with regions. The free market has decided that the global economy is a good thing, so price accordingly or gtfo.
If you're not careful, you're going to catch something.