There is more to it - the environment, and networking effects (so., the environment, which causes or prevents them). Only some of the human civilizations went all the way to the Internet, we still have people living as hunter/gatherers even today. So the advancement does not come from "inside" alone.
In any case, I like to think of humanity more like a brain, human = neuron. There are huge differences, for example, the human network also extends deep in time, not just in space (we manage to "network" with our ancestors, one-way from them to us, they gave us knowledge as well as all their tools). My point is "humanity" to me is a network effect. Place any modern human, adult or baby, in an prehistoric setting (20,000 years ago). Even if you gave them, let's say, an iPad-like device with all knowledge we have as of now, they would still not be able to do anything - because without the tools it would take quite some time to bootstrap. So "humanity" really is a lot - a lot - more than the sum of all humans, it's a giant ecosystem on its own.
I think depending on the environment you can have creatures with far higher intelligence than the average human and they still won't come up with modern technology. I think individual intelligence is clearly necessary and beneficial but overrated, that network effects are the main contributor, and that they don't appear automatically. We still have plenty of human societies right here and now that seem to be stuck.
Here's a Google Talk I once bookmarked: Joseph Henrich, professor in the Department of Human Evolutionary Biology of Harvard University, "The Secret of Our Success" https://youtu.be/jaoQh6BoH3c
An aside, arising from those thoughts, more of my own thoughts about something else: Each time you think about who "deserves" something, e.g. high pay, consider that most people who actually contributed so that the person even is in the position to achieve anything more than building a mud hut are dead, and another large amount of the contribution is "everybody else". That somebody can create a Dell or Microsoft, or invent theory of relativity, is because they are placed at the right points in the human network in time and space. What would they achieve by themselves in the forest? So much for "self-made" people. Self-made just like Newton who made the (much older) "standing on the shoulders of giants" famous. (https://en.wikipedia.org/wiki/Standing_on_the_shoulders_of_g...)