I'd wager that the developers pouring 18 litres of oily JS don't know that this is what they're doing. They've been told/taught that web sites are React/Vue/Wathaveyoo.
–
This checks out from my experience — a couple of jobs ago I saw a static website made entirely in React and I fully believe it was because the original dev didn't know you could make a website without starting from create-react-app. *So much* extra engineering, just to make a slightly worse product
It's something that came up a bunch of times in convos at FFConf - just because we taught it once, doesn't mean we don't need to repeat it again and again.
i.e. Repeat the teachings, repeat the learnings.