Core Web Vitals are now table stakes: they rarely win rankings alone, but failing them quietly caps how far great content can climb. The three numbers that matter are LCP under 2.5s, INP under 200ms and CLS under 0.1 — in field data, not lab tests.
Most failures we see come from four causes: uncompressed hero images, render-blocking third-party scripts, layout shift from late-loading ads or embeds, and heavy JavaScript hydration on templates that don't need it.
Work through them in that order. Image and script fixes usually take a site from failing to passing within a sprint; the JavaScript architecture fixes are what keep it passing as the site grows.