My basic issue with the debate about how democratic data centers are is that there's this product that 1 billion people like and use a lot, and 2 billion people hate. I don't think it's good for the majority to get to decide that the product doesn't get to be made and distributed, and while a lot of people don't actually mean this, a lot of other people do.
Widely hated products with a separate user base that still want them should still get to emit some amount and use some water, and if a billion people want them the emissions and water use are going to rise to be significant. In that case, what people should have democratic control over is whether they're harmed by the unreasonable externalities of producing the product, not whether the product gets produced at all or creates any externalities at all. What counts as reasonable here needs to factor in the size of the user base.