Core Web Vitals, the Honest Version
Three years in, what's actually still worth measuring and what's noise.
When Core Web Vitals launched, the framing was 'these three metrics are how Google evaluates your page.' That was always a simplification, and three years in we have a clearer picture of what matters.
LCP and CLS are real. Slow LCP and bad CLS hurt your users; users who are hurt bounce; bouncing hurts your rankings indirectly through engagement signals. Optimizing these helps everyone.
FID was replaced by INP, and INP is more honest — it measures interaction delay, not just first input. If your page is sluggish to type into or click, INP catches it.
What's noise: small absolute changes in any of these in the synthetic tests Google's Search Console reports. Real-user metrics matter; synthetic is a smoke alarm, not a thermometer.