It’s obvious that radiation isn’t the limiting factor, since, as you note, there’s no reason a satellite shouldn’t be able to radiate at least as fast as it gets power from the sun. I don’t know how this became a meme.
Yeah, I suppose another way to look at it is that ALL satellites have to radiate the energy they get from the sun (since 99+% of electricity used by electronics gets radiated off as heat). A datacenter is no different. All that is different is that quantity of energy both in and out, the ratios are identical.