Fortunately, that has—for the most part—changed. Today some boot companies make footwear that is only for women—designed on a women's last, which is narrower in the heel and has a slightly different arch than a men's last. Most outdoor apparel makers are also paying closer attention to how women like their clothes to fit, and designing them accordingly. Some women-specific pack makers are designing their bags specifically to complement the shape of a woman's back.
To part two of your question: What will help my performance? I think that whatever fits best, that's what. That's particularly true of footwear, but I think also holds for clothing and other gear. Take skis. For several years now, women have been able to purchase skis made just for them. Generally, these skis have a touch more flex (due to the fact the average woman has less muscle mass than the average man), are lighter, and have the binding mounts a little forward for easier turning. Now, you may not want or need those features—maybe you ski well and perform well on a man's ski. And that's fine. But you do have the option, and some women will find that a ski, such as Atomic's B:9 ($650 with Device 412 bindings; www.atomicsnow.com), makes them a better skier.
Quality-wise, though, no difference. The men's stuff and women's stuff uses the same materials and same manufacturing methods. I will accept the notion that a "lighter" ski is not as rugged, but if you take into account who is using the ski, that ceases to matter. Besides, when was the last time you saw anybody break a ski?