Asking out of ignorance. What tangible impact did Plato's work have on the world?
I can list how all the ways people that you listed made an impact on the world.
He also was Aristotle's teacher, and Aristotle was the philosopher who more or less created the entire scientific project (via people like Galen and Avicenna).
It's almost impossible to imagine what the world would be like today without them.
Aristotle took this framework and developed it further with the idea of inheritance. He classified things into tree structures (with great success) across many fields including biology, zoology, geology, psychology, politics, physics, and so on.
If anything, I would consider it an early version of "Signs and Signifiers".
Semiology is perhaps among the farthest removed from information theory, and computer science in general.