Why it matters
Fonts block text rendering or cause swaps and layout shifts. More than ~120 KB of fonts is rarely worth it.
How to fix it
Use one variable WOFF2 per family, subset to the scripts you need (latin), self-host (next/font), and drop unused weights and italics.
More performance rules
void perf reports 25 rules in this category. Core Web Vitals and bytes: LCP, CLS, TBT, TTFB, JavaScript, CSS, fonts, images, caching and compression, measured as the median of several runs on a throttled mobile and a desktop profile.
fcp-slowFirst Contentful Paint is slowtbt-highMain thread is blocked by long tasks during loadjs-budgetFirst-load JavaScript exceeds the budgetcss-budgetCSS transfer exceeds the budgettoo-many-fontsToo many font files are downloadedimage-budgetImage transfer exceeds the budgettoo-many-requestsPage makes many requestslcp-image-lazyLCP image is lazy-loaded