The two most obvious features here are elections (not referenda), and the judicial system. The latter adds an element of “village elders”, while the former makes decision-makers confront hard choices and their consequences.
That’s why direct democracy is considered rather harmful: just look at the clusterfuck that is Brexit for an idea of what happens when people are allowed to make fantasy decisions while disregarding their actual implementation.
As an analogy, consider trial-by-jury (managed by a competent judge) with having all of the locals decide all criminal cases once a month based on what they read in the (disappearing) local paper and on nextdoor. Who would you want to decide the punishment when the neighbor boy accuses you of touching him in funny places?
Brexit wasn't direct democracy; the public vote was a non-binding referendum submitted as an electoral strategum by the elected government, which then quit in favor of a new government of the same psrty, which decided—though in no way legally compelled to—to treat the vote as if it were a binding order in order to pass responsibility off onto someone other than itself.
In an actual direct democracy, the people would vote on the actual policy details, not vague generalizations only if and when it seemed likely to serve the political strategy of the ruling officials.
Brexit is not a failure of direct democracy.
Otherwise, if it's to survive, it does so by compromise, tradeoffs, bargaining, and leaving many people at least a little unhappy but not enough people unhappy enough to dismantle the system.
But in any case, in a direct democracy, if enough people want to vote on something, they can, regardless of how stupid it is. That would include Brexit etc.
Here, Wikipedia has a decently long article on it[0] to get you up to speed.
When you're done reading, maybe you can stop prevaricating in this thread and just state whatever case you're trying to make.