As other postings on this question acknowledge, discussing absolute importance is impossible. Why does anyone need to study or know anything in particular?
If we move out of that merely self-serving pragmatism of "how will I use this in my real life" thinking then we can look at the play as a cultural artifact, the knowledge of which adds cultural value to those who know it.
On a purely pragmatic level there, knowing the works that are considered part of the concept of "Great Books" allows one to garner a certain amount of social capital. One knows things that other people think are important, and the people around the world that have gathered lists of important titles are often influential in other ways (arguing which lists is another matter). But to know as much as one can about what other people know pulls the curtain back on certain assumptions. The English Renaissance, Christopher Marlowe, and Dr. Faustus tend to make a lot of those lists of titles that indicate social capital.
(The entire section contains 2 answers and 741 words.)