"The future of Google’s Core Web Vitals from a non-Googler perspective" by Peter Hedenskog https://calendar.perfplanet.com/2020/core-web-vitals-non-googler-perspective/
The Core Web Vitals are interesting, but yeah, I'd like to see an implementation in a non-Chromium browser. Plus, as with so many of these metrics, they're based on so many little heuristics that I can't help but imagine they will be tweaked over time... how can that be managed in a standards-based, cross-browser way?