I recently watched a video about death cap mushrooms (the deadliest, supposedly), and apparently about 80% of people still survive (requires prompt medical treatment), not that they would want to repeat the experiment. Apparently, the mushrooms even taste good.
Anyway, edible normally means "safe to eat," not just "possible to eat." (As you are no doubt aware). IIRC, Elmer's glue is considered safe to eat though not necessarily appetising.