What is the point of the Second Amendment if, according to the SCOTUS, citizens have no inherent, personal or private right to bear arms outside of service in a state-approved militia? Aren’t militia only needed when the state doesn’t approve them?

From The Supreme Court and the Second Amendment: Understanding the Court's Landmark Decisions:

The next major Supreme Court case about the Second Amendment came a decade after United States v. Cruikshank, and supported its conclusion that states had the power to restrict the right to keep and bear arms.

It started in Illinois, where Herman Presser gathered and trained his fellow German-American industrial workers in military drills, maneuvers and tactics. They called themselves the Instruct and Defend Association. Presser wanted to build a militia to oppose the private security firms like Pinkerton that were often hired by employers to break strikes and intimidate workers.

After Presser and four hundred of his fellow militiamen paraded through Chicago armed with rifles, he was arrested and charged with violating the state's laws against military organizations. Presser argued that the state's law was unconstitutional, as the Second Amendment granted him the right to form and maintain his own "well regulated" militia.

The Supreme Court affirmed the judgment it had made in the Cruikshank case: the Second Amendment did not apply to the states and so the states were free to regulate or ban private militias and guns in any way they chose.

The Court also interpreted the Second Amendment only to guarantee a state's right to maintain a "well regulated" militia, but not an individual's right to bear arms. In other words, outside of service in a state-approved militia, citizens had no inherent, personal or private right to bear arms for the purposes of hunting or self-defense.