Hiring a CSS/LESS CSS developer is crucial to create visually appealing, user-friendly websites. They ensure your site has a consistent, well-structured design across different browsers and devices. CSS/LESS CSS developers can enhance website performance, improve load times, and offer more design flexibility. Their expertise in LESS, a dynamic pre-processor, allows them to make CSS more maintainable, themable, and extendable. Thus, they can efficiently manage and update your site's style, saving time and resources, and ultimately, improving user experience and engagement.