Content is for sure on of the most important ranking factor. Without content everything else doesn´t matter so much.
Content is very diverse. It can answer questions, it can give tips & tricks or it can inform the user about news for instance. The text can be funny or sad, long or short.
Google and other search engines show those pages in the TOP 10 of the SERPs which provides the most relevant and appropriate content for the search query.
Does the content length matter?
Well in some cases yes, in other cases not.
Why should I get a page which contains text with more than 2000 words if I find my answer in a short article containing maybe 300 words. The credo of a search engine is: the user should be happy, he should find the answer to his question or find a solution to his problem. All pages fulfilling this requirements will get top positions.
If Content is King, Context is God