Financial statements provide a large amount of specialized, complex, information about the company.
If you know how to process the statements, and can place the info they provide in context with other significant information you have about the market, then you will likely be able to make better decisions about the company. If you don't know how to process them, you're much more likely to obtain incomplete or misleading information, and end up making worse decisions than you would have before you started reading. You might, for example, figure out that the company is gaining significant debt, but might be missing significant information about new regulations which caused a one time larger than normal tax payment for all companies in the industry you're investing in, matching the debt increase. Or you might see a large litigation related spending, without knowing that it's lower than usual for the industry.
It's a chicken-and-egg problem - if you know how to process them, and how to use the information, then you already have the answer to your question.
I'd say, the more important question to ask is: "Do I have the time and resources necessary to learn enough about how businesses run, and about the market I'm investing in, so that financial statements become useful to me?" If you do have the time, and resources, do it, it's worth the trouble. I'd advise in starting at the industry/business end of things, though, and only switching to obtaining information from the financial statements once you already have a good idea what you'll be using it for.