Sometimes I feel HN also is a similar attention sink, even Wikipedia as well. They also can draw you in for information snacking, and before you know hours have gone. Commenting and reading responses in HN is also another attention consuming loop.
In my case at least browsing Wikipedia is an assumed guilty habit, just like coffee.
What usually happens is that I browse /r/soccer or something similar and I get to the wikipedia page of a specific (mostly European) football league, like the Dutch Eredivisie or the Norwegian first league. Once on that page I click on a specific team (let's say Utrecht, Molde or Groningen) and before I know it I end up reading about the Hanseatic league or about the Spanish dominions in the Low Countries in the 1600s.