The super-hi-res pixel-shift modes that we're now getting on a few cameras are impressive, but they're always demonstrated with optimised studio test scenes - because that's the best way to show what they can do.
But the real world is rather different. Apart from the problems pixel-shift has with moving subjects, it's bluddy hard to achieve a properly stable and 100% vibratation-free platform without a heavy tripod and perfectly still conditions, mirror-up, electronic first-curtain, fast shutter speeds etc. I have Imatest for lens testing, which uses little square targets to read MTF sharpness, so you can cut them out and stick them to subjects in the field. I was amazed at how hard it is to get anywhere near the studio test readings.