While considered by society as attractive objects which value is directly proportional to looks, women are human beings that get discriminated (eg look at the wage gap). The right to vote only came up after WW2. Despite all this unfairness, discrimination and violence, women are human beings that deserve as much respect as men. Now concerning power it depends on what power is. There are many possible meanings, and definitions.
1. A political meaning.
2. An economical meaning.
3. A physical meaning.
4. A strength-of-character meaning.
Now the qualification of powerful is relative. And if we compare men to women, then:
1. Politically women are often discriminated. Which means very few countried get their presidents to be women, and except Germany's Kanzlerin, women are (because of discrimination), in general, politicallyy lacking power.
2. Economically women have lower wages unless they work for a public entity like a metropolitan area (ex: medical, police or firefighting branches), a state or at a national/federal level (ex: military or government offices). And even in the public sector like the police, they get promoted later or need more skill to get there, because they're discrimnated. This has an effect on their wages, income. So once again here women do not seem economically powerful compared to men. But of course wealth is transferred by the family and a rich man's daughter is rich. So the wealth aspect is rather insignificant. The income aspect is a bit more significant.
3. Physically, power is defined as work done per unit time, which means how fast one can work. Because of a relative, biological disadvantage (lower muscle mass, broader hips, more natural fat tissue) a woman can only be powerful (more than a man) if she trains real hard. Since most don't train very hard to get some unladylike muscle mass to become physically powerful, women are here once again not powerful, in my opinion.
4. Finally, in terms of strength of character, I've seen more devoted mothers than devoted fathers, more devoted GFs than devoted BFs. More caring ladies than caring guys. Also more honest gals than honest guys. If morality and love are power, then women are in general indeed powerful.
In the end you see that the power discrepancy is all but inevitable and fair. Discrimination can be fighted. And I've seen enough hardy lady souls to consider women powerful. But you can't say they all are. So I'd go in detail and "judge" one by one, not a whole group.