getting large datacenter level quantities of data from earth into space and back, and at low latency, is no triviality.

Latency is a huge issue, but so is bandwidth.

Land based data centers will have multiple hundred gig (and faster) fiber connections to the outside world.

Replicating that level of bandwidth on wireless links to a satellite in any sort of stable way is (as you said) no triviality. I would even classify it as near impossible.