Gatsby, an open-source framework, significantly enhances website scalability and performance by pre-building sites and deploying them to content delivery networks (CDNs), which reduces the likelihood of downtime during traffic spikes. This approach is likened to preparing for a party before guests arrive, ensuring that websites remain fast and reliable regardless of visitor surges. Industry professionals such as Brian Webster and Kennedy Rose highlight the framework's ability to mitigate stress and fear associated with site maintenance, as it allows updates without risking site performance. Tim Brown from Harry's notes that Gatsby's robustness enables seamless handling of high traffic without performance degradation, thus simplifying on-call duties for newer team members. Overall, moving to Gatsby not only provides tangible business benefits by preventing downtime but also offers peace of mind to developers and business owners who experience fewer disruptions and can focus on growth and innovation.