Why speed is revenue
Every extra second before a page becomes usable costs you visitors who never see what you sell. On mobile connections, which are most traffic most of the time, a heavy page-builder site can take several seconds to show anything useful, while a static site delivers the first meaningful paint in well under one.
Speed also compounds: faster pages are crawled more thoroughly, rank better on Core Web Vitals, and convert better on the same traffic. It is the rare technical decision with a direct commercial line attached to it, and, unlike most agency claims, it is independently verifiable in about thirty seconds.