[ncmncm]

It is, really. At one time, it was the only place the shuttle could get to; and the shuttle was the only thing that could get people to it.

Literally the only thing they can do at ISS, not better done with robots, is study how human bodies are affected by exposure to high radiation and long-term weightlessness. Which we care about only because people would be so exposed in ISS-like cans.

Now they are pushing the "lunar gateway", that likewise has exactly one reason to exist: SLS could get there. And, it will be a place for SLS to get to. And, even more useless. A thing in high orbit around the moon is absolutely useless for any other purpose, whether you are heading for the moon or beyond it.