Try this thought experiment:
Get 100 people different people together and try to get them to decide on the toppings for a single pizza. When you get at least 51 people to agree on toppings, you can order the pizza.
Then have the 100 vote for 10 of their number to represent them in the pizza topping decision making process. When 6 of those 10 representatives agree on toppings, the pizza can be ordered.
Now tell everybody that there are two pizza topping parties: The Hawaiian style pizza party and the Barbecue style pizza party and that they can vote for one of those two parties or abstain from voting altogether. When one of those choices has 51% of the vote, the pizza can be ordered.
The first group is the true democracy group. That is the most democratic and representative group, since each individual's views are represented. It would take about 30 years for a pizza to be ordered in that group.
The second group is the representative democracy group that has multiple parties. It will still take a while to order the pizza, because there are many different views being represented, but the compromise is going to be based on the representative views of the people involved.
The final group is basically a metaphor for our two-party system. A pizza will be picked fairly quickly, but chances are that people who dislike both options will not vote, and those who do vote will be voting for the option they prefer from the choices, even if they are not enamored with either choice. Sure, some people will actually love
the option that they vote for and would have made that choice even in a direct democracy, but they'll be a very small minority. The people in this scenario are only superficially represented because the options have been artificially limited for the sake of expediency.
The point is: the more representative a democracy is, the less quickly it works. Speed is inversely proportional to degree of representation in a democracy. This is the nature of democracy.