> The problem to me isn't social media per se. The real problem is self-discipline/control.

I'd agree with you if it was firmly established that all people have full, conscious agency. But the very existence of compulsive behavior personalities and addiction demonstrates that agency is unequally distributed.

While person A may easily be able to walk away from the dopamine bar by sheer force of will, person B may not. Person A's problem is surely with self-discipline, but person B's problem is with the dopamine bar.