The advantage is solar power in space. They will never stop getting sunlight.

There's a very narrow band of sun-synchronous orbit with consistent enough sunlight to make orbital data centers viable. Even with a tight constellation of 500,000 to 1,000,000 satellites packed into that band, it still doesn't make economic sense compared to what terrestrial data centers can do. At 500,000 satellites you're looking at maybe 50 GW of solar power. Then factor in the lifespan of LEO at ~5 years you're looking at hundreds of satellite launches daily to maintain that infrastructure.

Now work is being done for increasing solar access (Starcatcher) and others are working on improving LEO refueling and repair capabilities, but I would say we're decade+ away from establishing any true compute infrastructure in orbit.

In LEO you are about 50% of the time in the shadow of the Earth. Higher orbits or solar orbit (where you can get uninterrupted sunlight) require a lot more fuel and the further out the data center is, the higher the latency.

Solar and batteries get you through the entire day right here on Earth, plus you can shit in a toilet when you need to go on site to fix or upgrade something, not in a little tube. Plus you can probably just drive there instead of needing 15,000 feet/sec delta-v to get to orbit. And you can breathe. Surely the cost of batteries and panels do not exceed the costs and logistical pain-in-the-dick going into orbit will impose.

https://youtu.be/-w6G7VEwNq0?t=340