Answer:
It is important to have three branches of government in order to decentralize power. In a monarchy, all of the power is concentrated into one area, the monarch, which gives one singular person the power over a whole entire country. When you decentralize power with elected officials and voting, it allows for more diverse opinions and a more community-run democracy. I think having two parties can make voting and electing less complicated, but it is also difficult to categorize all beliefs and ideas into one party or the other.