The French and American Revolutions occurred at points where the arms and communications abilities available to governments were not majorly superior to what was available to the common people.
Back when conflicts were won by whichever side showed up with more motivated people with swords, then you could have Athenian democracy and the Roman Republic.
When expensively armored and trained soldiers could defeat larger numbers of people with just swords, you had the Empire.
When even-more-expensively armored knights on horseback could defeat foot soldiers, you had feudalism.
When the king's cannon could knock down castle walls, and longbowmen could penetrate plate armor, then you had kingdoms.
When firearms became widely available to the common people, you had republics.
When tanks, artillery, and machine-guns dominated, you could have totalitarian dictatorships.
..... provided the Admin Mod's don't tear my work off the editorial sidebar, though!