The ISS served all political purposes it could, and microgavity research can be served by private entities these days. (Especially considering that a Starship has half the internal pressurized volume of the entire ISS, at approximately one thousandth the cost.)

A permanent Moon base would allow research opportunities that private LEO stations can't: ISRU, low gravity research, the far side of the Moon offers unique opportunities for astronomy (any spectrum), etc. pp. Long term, who knows what additional opportunities it opens up.