Question

"How did anti-ERA activists like Phyllis Schlafly convince some American women that unequal rights were actually beneficial to women

Answer 1

Because they were anti-feminists and believed that feminism made women unhappy. This type of conservative argument has made many women agree with this and even today there are anti-feminists who view feminism in the wrong way, but who still use feminist conquests as if it were not a feminist achievement.