Is IMAX designed to take up your entire peripheral vision too? That would take more pixels... 4k might not quite be there yet. Also you might have sharper than average vision, Edward R. Grant.
For movies like Taxi Driver, yes. It's not worth it. The resolution is brilliant, but limited by the film quality. You can see the grain. But for movies shot in the last 5 years, it's f'ing amazing and miles better than DVD.
That's generally correct, the limitation being the image quality, and many of the bad Blu-rays are from poor masters or show the masters at their top quality, like Taxi Driver, in which you can see how bad the original film really was. This was often masked at home by the crap quality of home video and standard def tv. Once on HD formats, you can see the limitations of film. This can be improved, but often they don't bother with an expensive digital cleanup like they do the classics, like Star Wars. Some are even the beta video masters simply dumped to Blu-ray. But that's generally the cheap distributors. Same goes for streaming services.
