I am not a coffee enthusiast, it is usually just a breakfast or dessert beverage with plenty of milk, no sugar. But I have a couple of anecdotes.
There have been two (2.0) places that I could enjoy black coffee.
One was at work. There was a guy there who could produce fine coffee with a Mr Coffee and grocery store coffee, usually Maxwell House. What did he do differently from every other office coffee pot in the world? I don't know, but he had The Touch. And he didn't even drink the stuff, made it as a service to the lab.
The other was the only good café in Hawthorne Nevada ca 1994, visited daily for five months of an engineering project there. Regular restaurant urn and restaurant supply coffee, but it was also very good. Perhaps it was the water, they had an elaborate water purifier because the city water supply was vile stuff from an over-pumped desert aquifer. (The Army installation there used surface water, snow melt off the mountains in a little reservoir of its own. So pure it only needed sand filtration to get the dust out. Great water... but nobody there made coffee with it that I ever saw.)
Another project that I was on used distilled water in the coffee maker. The coffee was nothing special, but the pot never limed up.