I've heard a few things on this. One is that there were a few high profile but very bad cases in the 80s, kids getting kidnapped and trafficked with law enforcement not really willing to even look into it. The odds are infinitesimal, but the cost of the negative outcome is very, very high. Second is kids getting run over by cars. Comparatively that happens all the time. Third is a general breakdown of social connection with people in your neighborhood.
When I was a kid in the 90s, I knew multiple kids who were severely injured by cars. For whatever reason, this did not seem to have any impact on my mother's parenting and no new limits were placed on my freedom as a result. For the record though, one of the kids I knew who was hit was leaving the property of their school with plenty of adult supervision around at the time of the collision (and received a large settlement from the school).
Adam Walsh was 7yo and abducted from a Sears. His parents left him to play Atari while they shopped.
They made a movie about it in 1983. Politicians introduced new laws around it.
His father John Walsh went on to host Americas Most Wanted on TV for 24 seasons. Prime time TV whipped up a culture of fear for that entire generation.
Kids growing up with that culture are parents now. Not surprised to see these results.
