Isn't the case of physical labor justified? Here I refer to where the article states that pregnant women doing physical labor often face discrimination upon ask

Isn't the case of physical labor justified? Here I refer to where the article states that pregnant women doing physical labor often face discrimination upon asking not to lift too much weight. This is an example where pregnancy directly makes someone less able to do their job. That seems like a valid reason to want to pay them less, or to no longer hire them. Unlike the more general call of equal pay for equal work (regarding the wage gap) here the demand is essentially equal pay for worse work. I assume the argument is that affirmative action is needed to get more women at the top. However, not taking affirmative action is rather different from active discrimination. I'd like to qualify that I tend to support affirmative action, but I do not think that forced affirmative action works. If we force companies into such action by law, they have every reason to follow the letter to the least amount possible, and totally ignore the spirit of the law.