Even if there was a working phone network and phones when we were hunter gatherers, this wouldn't allow us to grow cities.
All inventions work off each other, but if we count them without prerequisites:
Agriculture (farming / animal domestication etc), ie being able to quite reliably produce a lot of food, is the most important innovation and invention for humanity.
Next, still not information but the industrial revolution and engines and mass scale production. Without this we would depend on humans and animals to do the work, and I for one do not like the idea of a modern slave industry, but even beyond that we couldn't use economies of scale, which actually allows for absolutely bonkers progress.
> the industrial revolution and engines and mass scale production
This was enabled by the printing press. Immediately prior to the industrial revolution, printers printed how-to manuals on every topic they could think of.
It's not a surprise that the industrial revolution occurred in the area that invented and widely adopted printing presses.
Even if there was a working phone network and phones when we were hunter gatherers, this wouldn't allow us to grow cities.
All inventions work off each other, but if we count them without prerequisites:
Agriculture (farming / animal domestication etc), ie being able to quite reliably produce a lot of food, is the most important innovation and invention for humanity.
Next, still not information but the industrial revolution and engines and mass scale production. Without this we would depend on humans and animals to do the work, and I for one do not like the idea of a modern slave industry, but even beyond that we couldn't use economies of scale, which actually allows for absolutely bonkers progress.
Then perhaps writing and reading, and networking.