The point of datacenters in space is about control not economics. They dont want the masses which they are trying to replace with AI and robots to have access to the datacenters running everything.
You might be on to something. Starship is moving its launch facility to Florida. Elon previously suspected a sniper shooting at the SpaceX rockets. Moving the launches to Cape Canaveral would make them much harder for a sniper to target. And his terrestrial data centers are easily accessible for anyone who has a grudge with him. Moving those to space would also isolate him from the masses uprising.
Again, we're getting closer to Hyperion Cantos here.