They matter because Google uses them as a ranking signal and because they capture what users actually feel: does the page load quickly, respond when tapped, and stay still while loading. A site can look fine in a lab and still fail these on real devices and networks.
You pass only if at least 75% of real visits hit the "good" threshold for each metric. Field data from the Chrome User Experience Report is the source of truth, which is why testing on real conditions, not just your fast office connection, is essential.
Updated July 2026
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