This article is about small data centers not being so controversial (less power demand, water demand, less noise). An argument could also be made that a small data center is also less investment risk: if the AI demand is just hype you didn't lose as much building a small data center.
You’re correct about the costs. My main point is that data centers are not necessary for you and me to get around on the web. They will be used to store information that can be used for marketing. That information will be quite valuable. I know from my work experience that demographic data is expensive.