Why are we limited to the Democrat and Republican parties? What about other political parties?

[AgnosticBoy]

For all of my voting life, all I hear about is Democrats and Republicans. Eventhough, it's two parties but I still feel like they have a monopoly on our political system.

I've seen other political parties on the ballots, but it doesn't seem that they have a good chance of winning. They get little exposure, the mainstream media certainly doesn't cover them as much as they do the Democrats and Republicans. I remember when Kanye tried to run for president and he detailed some of the process. It seems that there are different procedures and qualifications in each state. There should be one national standard, and it should be easy.

Here's some historical context:

When Americans go to the polls in November to elect their next president, it’s almost certain that they will be selecting between only two candidates: one Republican and one Democrat.

In fact, since 1852, a candidate from the Republican or a Democratic parties has placed either first or second in U.S. presidential elections, except for one. In that election, in 1912, Theodore Roosevelt, a popular former Republican president, ran as a “third-party” candidate, and he came in second place, losing to Woodrow Wilson.
And before the Republican Party and the Democratic Party were the two major parties, the Democratic Party and the Whig Party were. Before that matchup, the Democratic Party and the National Republican Party were the dominant two. And before that? The Democratic-Republicans and the Federalists reigned.

Source: The Washington Post

For debate:
1. Why is there a lack of alternative political parties in government office?
2. Are there benefits to having more parties to vote for?