Dan Luu reports that Google penalizes his pages in search rankings because they don't include enough CSS and JS. It's not really half of the websites; it's the half you're being guided to.
As an aside, I vouched for the comment (which still shows as [dead]), because a quick glance at posting history shows just the singular comment as dead, with no indications of twattery to justify it. It's like a commenter with not-interesting post history just got a single comment randomly killed.
I found this post [1] but it seems a but outdated and references AMP, which Core Web Vital metrics are supposed to replace (right?).