This is just an opinion based on my experience. I received a letter in my regular mail box, inviting me to nextdoor.com with the code of "my community". It does not feel right to put your name and your exact location and share it with thousands of peoples in your town when you sign-up. But anyway, I decided to give it a try. I saw a neighbor complaining about the moderator, deleting his post. I thought, he may was posting some spam or something. After some days using the APP, I decided to post something, that the members thought it was funny, I also knew it was. Nothing bad, nothing offensive, everything cool. Suddenly, my post disappear. A moderator deleted my post. So you can't have fun with your neighbors on Nextdoor.com because apparently they won't allow it.
Maybe, the warnings, the bad news, and gossips are more important for them. I think Nextdoor.com is risky, boring, and not for me. I did not like it.