As a consumer of information, your time, attention, and even your action of clicking open a link is a valuable commodity. Websites glean money from advertisers based on the number of views, likes, clicks, etc. Both legitimate and hoax news sites have a stake in trying to get your attention, but reliable news outlets also have journalistic and editorial standards that (usually) keep them from resorting to click bait or outright emotional manipulation. Their primary purpose is to provide factual information to readers. Hoax news sites and many hyper-partisan news sites have fewer scruples. Often, these sites' primary purpose is to make money.
For a more detailed account of how fake news sites can make money off of us, here are articles from the LA Times and Washington Post that outline important connections between advertising and fake news:
Journalism is a highly competitive field right now. Professional journalists have training and experience not only in things like interview techniques and fact-checking, but in ethics and things like libel law. While journalists are people and subject to biases like the rest of us, in their professional capacity journalists working for respected news sources strive for objectivity.
Below is a link to the Code of Ethics for the Society for Professional Journalists. It outlines core journalistic principles and sets standards for reporting:
Almost all news outlets (legitimate and fake) rely on advertising as a source of income. Professional journalists and editorial staff are paid to do quality work, including fact-checking, conducting meaningful and ethical interviews, and striving for objectivity. They work quickly, but it still takes time, effort, and money. When readers are drawn to "news" not to learn information but to confirm pre-existing beliefs or to feel the sensation of being outraged, fake news sites draw traffic from legitimate sites.