Does a PageSpeed Insights score directly affect SEO?

No. The 0–100 Lighthouse performance score shown in PageSpeed Insights is a controlled test result, not a ranking factor by itself. Google uses real-world Core Web Vitals among its broader page-experience signals, so data from actual visits can matter even when a single test looks good or bad. Use the score to find performance problems, then evaluate those findings alongside real-user data, content quality, and search relevance. Google's Core Web Vitals guidance explains how the real-world metrics fit into search.