Starlink already solved those problems, they do 200 GBit/s via laser between satellites.

And for data centers, the satellite wouldn't be as far apart as starlight satellites, they would be quite close instead.

No they didn't. 200Gb/s is 25GB/s, so... They could run 1/36th of a single current-gen SXM5 socket. Not even any of the futuristic next-gen stuff. 25GB/s is less than the bandwidth of one X16 PCIe3 socket. And that's already assuming the best-case scenario, and in reality trying to sync up GPUs like that would likely have loads of other issues. But even just the sheer amount of inter-GPU bandwidth you need is quite extreme. And this isn't some point-to-point routing like Starlink trying to get data from A to B, this is maintaining a network of interconnected systems that need to communicate chaotically and with uneven demand.