Yes and No.
Financial statements are a product of accounting language that aims to translate all the activities within a business into a common base. For some areas it works very well, ie loan repayments flow can be accurately described as all the terms are within the financing document. For some other areas, it's insufficient. What if your star sales employee is unhappy with their salary? You wage costs may be low, but in fact you have a impending revenue drop on your hands as employee resigns.
Because of the limits of what financial statements can do, I would never rely only on them to evaluate business performance. They can provide you with an idea of where to look, but talking to people running the business and understanding the industry will provide a more complete picture.