No, it is very much different. Your example of sameness (help clients and keep things running smoothly) could be said of computing versus hvac equipment. So what if you still help clients? You do that at McDonalds too! So what if you have to maintain something?
You have to maintain and keep any number of things running smoothly, from a slushie machine to a high end server farm. That doesn't make them the same, but good try at trying to pretend that someone could be parachuted in from 30+ years ago, or even 20 years ago, and be able to do the job today.
No. Way. It is an ENTIRELY new field. New management techniques. A new place in the business place. More widespread. More complex, by FAR in a variety of different ways.
But all of this is a red herring! Who the hell cares how many people of what type were in the computing field $x years ago. It is an utterly meaningless metric. So many things change over decades, not only the field itself, but society as a whole, schools, societal norms, you name it!
Yet, you're picking on some unrelated example, and thinking that it has to do with what's inside. It isn't. Look at the world in its entirety.
Perhaps there are good, high paying jobs in other fields? Perhaps there are fewer women that want to be in the workplace? Or, any number of things?
Further -- sexism is about equal opportunity, not equality. Women are NOT men. They are NOT THE SAME as men. At all! Why?
Because we're using the plural, and the plural allows one to use statistics to validate data on large sets.
Individually? Sure, there are smart women, educated women, women that WANT to be educated, and women that beat out men in many metrics. Equality is all about ensuring that even though metrics exist, that stipulate that a certain group tends to be "this way", that the *individual* gets the change to show their own skillset.
So, it is absolutely, 100% not wrong to say "Women are not well suited to technology fields in general". Because it is *true*.
The very important thing, however, is that "no one is left behind" due to the above valid assertion. Because yeah, individually, there are some kick ass women out there, in this field -- and others that can contribute equally well.