Anyone I've spoken to in meat space has shared a collective sigh when I mention the general flavor of discourse on Nextdoor. I live in a bubble, but I also make efforts to poke my head out from time-to-time and I talk in-person with a handful of people who are definitely don't think they're in my bubble and vice versa. On the whole, people are a nicer in person than online. Maybe I am too?
Nextdoor is not an open platform nor a community run endeavor and with that come certain very real limitations on expectations. Nextdoor is a commercial company with commercial interests and that translates directly into how the service is and will be run. I think that's important to accept and OK especially because it can be very useful.
Using Nextdoor and not losing access to the service is like walking into a store. You're no longer in public. Put on shoes and a shirt. Don't yell fire, don't dox people and don't expect the freedom you have in the comfort of your own home. This is a private place that the public enters. The rules are sorta there, but can change at any time, are enforced in a myriad of layers with the community moderations having the least power.
All this said, I've had some good interactions with Nextdoor corporate. The staff has been reasonable and dispassionately explained various aspects of the moderation system to me. I recommend that you reach out to them too!
Since I want to discuss moderation on Nextdoor, I was advised to create a special group because otherwise it violates the guidelines for civil discourse. The guidelines are violated all of the time, but that is the guideline so the dude abides and creates a new group.