Men and women, because of their inherent physical differences, are not equally suited for many tasks

Men and women are different in many ways. They each have some characteristics, which may be from physical to emotional, that make them better suited for certain tasks.
Let us take the example of lumberjack. This task requires the lifting of heavy wood. Men with their higher physical strength are more suited for this job in general. Consider another example of a circus acrobat. Women are inherently more flexible and hence are more readily suited for this.

While there are certain tasks that require a particular physical ability, majority of the tasks these days are generic. With the advent of technology, and its proliferation into our day to day lives, the strain on human physical strength has eased. We no more need to fetch the firewood to lighten our homes, for that we have electricity. Most of the tasks at workplace requiring physical strength have been mechanized. People are needed mostly to operate or monitor machines. We no more need bare hands to fetch rocks to build a wall. We have all sorts of lifting machines to do the same task, which can easily be operated by men or women.

The difference in suitability will differ depending on the geographical factor. The terrain, the advancement in technology, the population of a town, all of these play an important role. A rural town, at the edge of a desert, in a third world country, will more likely depend on more physical tasks from its people. There, the tasks may be divided between men and women. But a similar town in a developed country, with all the technological advancements, may not have such barriers.

Men and women have different physical difference, but the extent to which these differences determine the suitability for tasks depends on a lot more other factors than just the mere physical differences.