Well outside my field, but I was under the impression that getting the energy into the GPU (solar) was not the problem. The problem is getting the heat out. It takes a lot of surface area to radiate out the heat that GPUs produce. Maybe it ends up economical, but just having it in space adds in a bunch of challenges, not least that once it's up there you can't send in a technician to troubleshoot.
And if solar panels drop another 90%, why not just slap them on earth?
And if solar panels drop another 90%, why not just slap them on earth?