Definitely true. If we look at how local cities were governed in the eastern part of the Roman Empire it was basically as democratic as you get in that time.

Organized in what was known as the Boulè, it was basically a democracy of the rich.

The democratic tradition in antiquity is hugely overblown.

Athens of course being the prime example of a democracy, but it has absolutely nothing to do with democracy as we know it today. It’s a democracy based on privilege and wealth.

Same goes for Rome’s Res Publica, which was never a democracy. Just because something was a republic does not mean it’s democratic, and obviously Rome developed to an extremely autocratic state.

I’d argue it’s easier for civilizations to expand fast when connected to rivers. The larger a civilization the sooner it’s autocratic.