Why are humans so successful a species?
Because they externalize.
The first example of this process came when Homo erectus externalized part of their digestion by using fire. Fire helped early pre-humans to boost their nutrition, both the availability and the quality, by cooking meats, tubers and eventually grains. The cooking process releases nutrients and reduces tough materials to palatable fare.
Next comes tools. Homo Sapiens and Homo Neanderthalis, both used tools as a means to enhance their lethality and their efficacy in the exploitation of resources (hides, bones, stones, wood). They used simple tools to externalize their bodies’ capabilities.
Then we have machinery which allows humans to leverage physical forces like gravity, wheels, pulleys, levers and machinery in general. A human with such tools often represents a human that is twice, ten or hundreds of times as powerful or strong. Fire also is used as an advantage here to melt ores and clear land. A human can massively extend their power by externalizing through a crane, mining truck or sailing vessel.
Next we have externalized information. Information stored outside a human’s brain, whether it be in books, pictures or in digital formats, allows a human to be many hundreds or thousands times smarter (in knowledge) than a human without such externalized information.
Finally we have the advent of artificial intellects. AI. Humans can now take advantage of not only their own mental capacity with regards to problem solving, but can use increasingly useful and expanding artificial minds. These minds will augment a single human such that they will be able to not only think as one but think as many thousands.
Fire for cooking, tools for hunting, machinery mining and building, information storage for memory extension and now AI for thought expansion, all have provided externalized capabilities that give a single human the power of millions.