They don’t have any advantages at all.
People point to the cost of land, but if being physically inaccessible isn’t a problem, then there are lots of cheap places on Earth you can deploy data centres too at far lower cost than launching them into orbit.
Desert land is free. Floating data centres in the middle of the pacific is free.
If a state, or even rich billionaire, wanted to take out your data centre in low earth orbit, it's only a few million dollars to launch a retrograde rocket which explodes into 10 ton of shrapnel, or even less to forget the orbit and just launch it directly up.
For now there's a regulatory oversight advantage (or rather lack of same).