all those negative reviews are by people who used a UK network called Streetlife that Nextdoor bought and took over. So that’s understandable–the privacy settings were completely different.
ND lets you hide your street number, but these reviewers are saying that if you do that, your exact home location can still be seen on a google map. If so, this is contradictory to ND’s stated policy that they shield from google/search engine results
https://help.nextdoor.com/customer/en/portal/articles/1416218-privacy-and-safety-on-nextdoor
Personal information shared on Nextdoor will never show up in Google or other search engines.