I'd judge it this way:
Can I see any difference in my prints between the output of say a £400 X-T2, a £700 A7Rii (sourced from MPB) and a 10-15x more expensive £7000 hassie body.
If I can't see any difference in the prints, I might need to either:
Print bigger!
or
Think very carefully about why I want the Hassie.
Is it the practical image quality for my use case? Or is something else (say the traditional romance and the glamour of a famous Chinese drone manufacturer brand).
If it were the latter, I might want to have my sanity independently checked, or be sufficiently wealthy that the price is irrelevant.
I personally have no issue with someone who is rich wanting to use their money inefficiently just because they can. I'd feel a bit sad for someone who can't really afford it, but who lets the fantasy/glamour get to their head. The new-car sheen wears off fairly quickly, then you are left with the real world.
That's my take on it.
One practical problem in all this is it is not very easy for most people to get hold of and test expensive products in advance of purchase (at least not where I live). That means your initial GAS is driven by hearsay and your own tendency to hype up the worth of a prospective purchase in your own head untempered by real world practical experience. It's usually my experience that GAS creates rose tinted glasses that only hands-on experience can illuminate properly. It's especially the case with high end products that are way beyond your usual experience. The reality can often be less than hoped.
It's an eye opener to me that no one appears to be able to see any image quality difference between m43 and GFX with my 12" prints. The printer/inkset/paper is the primary determiner of print quality here, not the camera.
For me the most benefit is the digital teleconverter. I have 28-63mm zoom range with such small and conveniently balanced camera. On MFT you can mimic this with a good and relative small 14-35 f1.4-4 lens, still with GFX I have that mighty 100MP resolution at wide end, and there is the other benefit beside printing size: documentation - capturing huge amount of data in one exposure. I can always print large, inspect details zooming in, or I like the ability of post composing. There are lot of situation when I just don't have enough time for thinking of right the composition, or later I'd cut off large parts. Example from yesterday:
Post-cropped image
View attachment fc6fca9050bc4f708278f122c5ba493f.jpg
The shot
And the image quality, resolution is the half of the story, other half is the camera itself. You may not interested in quality of the body, overall construction, but in my case Fuji just nailed it, I've been hungry for a thin and premium build quality rangefinder camera with large sensor and small lens, and high magnification EVF, also high resolution tilt screen has been also my expectation, where the A7CR utterly failed. If Sony has came up with GFX100RF like ILCE body, I'm almost sure I'd never go for the RF, even with my excitement for MF sensor.
