Even though current gender roles discriminate against men they are necessary due to the biological inferiority of women.
I hope you just worded that wrong. The average women is only inferior in terms of overall body strength, not biological in general.
Also gender roles don't discriminate against men. Women have "advatages" in some social areas, and men have some in other areas. There is some differences, because the 2 sexes ARE different. Treating both the same as if they were the same is foolish, because they simply aren't. It's like putting all athletes in a sport competition in the same league.
In my opinion nowadays we achieved pretty much gender-equality in western countries. The only thing where women are still in a disadvatge is income. In some areas and firms women earn less for the same work even if they are as qualified as men there. This is what still needs to be fixed.