I have two theories.

1. A bunch of these people are scared of needles and are looking for any excuse not to get a needle. They don't want to feel alone so they spread lies so others don't get it either.

2. They want people die and get off on that.

You can use Revanced Manager to remove the ads out of the app. Just sayin'... As a 'fuck you' to Reddit, if you insist on still using that site.