Site speed affects two different things at once: whether Google ranks you, and whether the visitors who find you stick around. Real numbers on both, and what actually moves them.
Local search has a short list of things that genuinely matter and a long list that mostly does not. Here is the short list, in the order worth doing them.
More people now start the hunt for a contractor by asking an AI assistant. That shifts the target from ranking on a page to being one of the few businesses actually named.