For one, Florida requires that all corporations have them (unless that power is reserved for the shareholders in the Articles of Incorporation). When you incorporate in Florida, you’ll be tasked with writing corporate bylaws.
Just as important, though, is that writing corporate bylaws is critical to running your business smoothly and efficiently. For example, every corporation must appoint directors and corporate officers (President, Secretary, Treasurer, etc.). The bylaws are where their duties will be explained. Even simple procedural issues, such as when and where the annual shareholders meeting will be held, are addressed while writing corporate bylaws.