The history of democracies is usually told as a rebellion against an overweening King - George III for America, Louis XVI for France. In England it is King John, in 1215, and the rebellion gave rise to the Magna Carta which constrained the powers of a king, and providing for a separate body (of barons) to enforce it.
Cromwell's rebellion against Charles I is not often portrayed as democratic, though the accession of William & Mary in 1688 after James's restoration was notable for the English Bill of Rights which further constrained the King's power and in effect made Parliament sovereign.
The history of democracy can be seen as successive (and expanding) answers to the questions:
Who gets to vote?
Who gets to speak?
Who gets to set the topic?
With a single sovereign, or a single parliament, control of the latter two is still tricky; legislative agendas, though longer than historically, are still constrained, and the introduction of legislation is more often reserved to government or elected legislators, and more rarely allowed by referendum.
In a deliberative body, elaborate rules are adopted to ensure only one person speaks at a time.
There is an inherent funneling of debate because of these procedures.
Conversely, online there are millions of conversations happening in parallel, topics are introduced daily, and votes are largely spurious.
The challenge is help these conversations to focus, converge and produce action.