What benefit could competitors get from that information?

It doesn't even have to be competitors their suppliers would love to know the total amount of widgets that they'll be buying. That way they know if they're the single supplier

The ability to improve their data centers, of course. Google is the company that launched data centers with commodity components.

It tells them exactly how much they have to invest in hardware buildout to stay competitive with Google in terms of raw compute.

This is right up there with being able to predict a competitor's total manufacturing capacity for the next year because you have hard numbers on their raw material purchase.

A friend accidentally told me not just how many servers Google was deploying for Bard, but what they were putting in them and the volume of the scale up.

A competitor with that information might have made a rush on a supply-constrained component market or negotiated longer term pricing agreements.

The strategic advantage, by definition, is something you, as a company, don't know what it is. If you know, then people leaving your company take the information to competition and the it's not strategic nor advantage anymore.

So, given that you don't know what makes your company better then the competition, it's better to hide everything you can so you don't accidentally disclose useful information. God forbid competition discover your own strategic advantage before you do.

And this one in particular is a high-ticket trade secret; it has been for decades, long before the AI push.

Power and water consumption number revelation goes directly to ceiling on maximum compute and relative compute efficiency. It's handing to every competitor on the planet (including China) "Hey, here's the raw situation on how far along we are on our total capacity to do anything."

... whether this should be a trade secret (since power and water are both shared resources with the surrounding community) is a reasonable question, but in the ecosystem where it is, Google having this data public and their competitors not is a problem.

If they are so good at it, they should push to make that the bare minimum and get to hold all future datacenter permits.