In a lot of cases, it's the only way that municipalities can submit bids for projects they want. And in the commercial space the bidding process is usually confidential. So it's just basically a requirement of public private partnership.

Of course the municipality could just say that they don't want the project and they won't submit a bid. That's fine too.

They'll tell you it needs to be confidential "for commercial reasons". They always do.

Because municipalities want to be able to collaborate in the early stages of a potential datacenter project, when it's not fully nailed down and may never happen. A world where municipalities aren't allowed to keep secrets is a less transparent world, where Meta dumps a fully formed datacenter project on the local government and nobody has a chance to suggest that residents would prefer it on the other side of the creek.

There are valid uses. McDonalds may not want Burger King to know they're planning to build a new location in Smallville, 'till they actually break ground, or vice versa. Don't blabber to everyone that the City wants to expand a park, so neighboring property owners will know to demand top dollar. Etc.

But yeah - honest uses are pretty limited. Which limits we can hope will be tightly enforced by new legislation.