This conversation about jobs reminded me of the story that a streamer I follow had recently with his job hunting. Basically, he saw a job posting, applied for it, three weeks passed, posting was still up so he called for some info.
THEM: "We actually already filled that position"
HIM: "... ( 'w')"
HIM: "You could at least take the posting down then? It's on *location*"
THEM: "Sure we'll do that right away".
Fast forward another 2 weeks (to this monday), the thing is still up.
tl;dr: It would be awesome if people took down their ads and flyers when they're no longer useful for anyone.