(author here) this is true! That's what I'm trying to explain in the `state` section of the article.

State lives in a "global" and the component is modifying it. So it's "leaking info out".

It's hard to make comprehensive mental models that cover all the bases and leaves nothing out

i considered adding "mutate a global" in there but didn't feel like that was relevant to @iooi's comment. maybe i should've quantified "the only thing" a bit more :)