I’m calling BS on this. Biggish claims that are so vague as to be borderline unverifiable, no scientific basis laid out.

https://www.wikihow.com/Make-Mineral-Water

It's a thing, just a very niche thing. There are fancy walter filtration systems that put minerals back so it's more controlled. I suppose this is useful when you're living in America, where everything is chlorined to death.

The whole thing is slop.

Why x Matters: is absolutely a tell

You clearly haven't tasted coffee or tea brewed with hard water. And I don't see why yeast or fish wouldn't be more comfortable in some range of mineral composition than another.