Site speed is a business issue
A slow site loses rankings, loses patience, and loses money, in that order of visibility and reverse order of importance. This section treats speed as a business number. The site you are reading is the demonstration: view source, run Lighthouse on it, check its field data. That is the argument.
First articles land here soon, starting with what actually matters in Core Web Vitals. The Core Web Vitals glossary entry is the primer meanwhile.
Terms for this section
Full glossary-
Core Web Vitals
Core Web Vitals are Google's three field-measured user experience metrics: LCP for loading speed, INP for responsiveness to interaction, and CLS for visual stability.