This is the thing I don’t get. Everyone talking about the “how” but nobody talking about the “why”? It makes literally no sense.
Because people have to compete just to have sand doing math for us? The why is that it's high time we stop worrying about how much compute we have. Certainly filling all solid planets in the solar system with computers is not nearly enough computation as we want (I'm not even talking about AI specifically).
Snake oil, like bitcoin.
A lot of people will invest in this because "it's the future" and a few will make a lot of money on that.
The only thing that keeps bouncing around in my thick skull is something "data-center sized" whatever that means to them could hold some interesting objects. 2 Peta Watt laser, Rods from God, Tactical nukes, Miniature Rail-gun to quickly eradicate other satellites, Off-Planet archives of stuff, Doomsday clusters of brainwave transmitters to shut off all the humans or force everyone to defecate at once.
Those are just some guesses. Some of those could also explain the "why" for SpaceX Falcon Heavy and it's future iterations. It can carry 63,800 kg (140,660 lbs) to Low Earth Orbit and that load capacity will only increase with future versions.