Hiring a cross-browsing developer is crucial for ensuring your website or application functions flawlessly across different browsers and platforms. They bring expertise in handling browser-specific quirks, compatibility issues, and performance variations, leading to a seamless user experience. They also help in reaching a broader audience by making your product accessible on various devices and browsers. Their skills contribute to better user satisfaction, potentially increasing your customer base and revenue. Additionally, they stay updated with the latest web standards and technologies, ensuring your product remains modern and relevant.