Hiring a Bootstrapping developer is beneficial because they possess the expertise to create responsive, mobile-first web applications. They have a deep understanding of HTML, CSS, and JS, the core technologies that Bootstrap is built upon. Their knowledge in using Bootstrap's pre-designed templates, styles, and components, can expedite development, ensuring a faster and cost-effective project completion. Moreover, they can ensure your website's compatibility across different browsers and devices. Their skills can ultimately improve user experience, increase engagement, and potentially drive more traffic to your site.