My impression of nextdoor based on my admittedly very limited usage was that maybe 5% of people (the usual paranoid types) used it as a sort of unofficial neighborhood crime watch, and 95% of everybody else used it to share pictures of local wildlife, organize barbecues, complain about the weather, and share old people memes.

I'm sort of biased though, I find mild gossip to actually make a place feel almost "comfy" and "lived-in". It's like the vibe of a local diner or church meetup, where nothing really happens in the community so anything minor (from a new car a neighbor has parked outside their house, to the loud kids who collect sticks to pretend-fight with and store them in a pile behind the mailbox, to the "crazy" party that the young couple had in their backyard last night with half a dozen friends) is a subject of minor gossip and banter and speculation.

I honestly bet 90% of the bad rep nextdoor get is purely a generational thing because nextdoor is basically just social media for older people and young people just don't really get how old people use social media. Notwithstanding the email/notifications topic here of course.