Writing vanilla CSS often involves the hassle of coming up with proper class names, which can become tedious. That's where Tailwind CSS shines, as it allows you to apply styles directly with utility classes. However, repeatedly using the same classes and writing many of them can become cumbersome. To simplify this, FlyonUI introduces semantic classes to streamline your work. For example, instead of writing multiple utility classes for a button, you can simply use `.btn`, and your button styling is ready to go.