"While I don’t think there is a definition that universally applies, I’ve found a definition that works relatively well. Exclude any page that has ads. Remove them if they use Google Analytics or Google Fonts. Remove them if they use scripts or trackers. It’s a hard filter that blocks the most popular sites. Forget YouTube, Facebook, Reddit, or Twitter. Forget the major news sites."
That's not a definition that helps us understand the qualities of a quiet web. Sometimes, thinking in metaphors can really hinder our ability to explore all the design space and not just the stuff that the metaphor borrows from.