The definition of "mint" itself seems to age poorly. Old overpriced "cult" lenses seem to be particularly prone to be classified as "near mint" if there's fungus in only half the elements, and dents only on the front rim. But I rarely look at those kinds of items. Once something is advertised as "collectible", I'm suspicious from the outset. I don't need any overpriced bookends, collectible or not. I'm a shooter.
As far as counters go, just like auto mileage odometers, these can hypothetically be reset by unscrupulous sellers, but probably rarely are, since they're not the type who would likely want to go to all the extra fuss doing so. Fuji had a recommended shutter maintenance interval of around 1200 rolls or so; but many people have had no issues well beyond that. It's just a recommendation. I bought my GS690ii with 350 on the counter, and will never go over a 1000 in my life. My GS690iii had only 15 roll runs through it, so for all practical purposes, might as well have been a brand new camera.