The relationship has not changed, only the stakes: each second of load time cuts conversions measurably, mobile users abandon hard after three seconds, and speed feeds both classic rankings and AI crawl depth. For most SMB sites two hours of image and script cleanup recovers the worst of it.
Speed is the quietest leak in the funnel because nobody complains, they just leave. The research consensus has been stable for years: conversion probability falls off a cliff between one and five seconds, and the mobile-data reality of your actual customers is worse than your office wifi ever shows you.
In 2026 there is a second reader with a stopwatch: crawlers and answer engines allocate attention by efficiency, and slow sites get sampled shallowly.
The eighty-percent fix
Compress and resize images, which is usually half the total weight. Remove the plugins and scripts nothing uses. Enable caching. Serve modern formats. None of this needs a rebuild, all of it is measurable the same afternoon on PageSpeed Insights.
If the site is still heavy after that, the architecture is the problem, and that is a different, honest conversation about rebuilding.