This is what I thought too. There is nothing described in the article that can't be accomplished with a closed group on Facebook, which we use for our apartment building in San Francisco.

The main feature I wouldn't mind having, if NextDoor has it, is a way to share tools and other things that I have with my neighbors. For example, I have some power tools, excellent specialized cooking gear, commercial juice press, bike repair stand, etc. and plan on buy a commercial vacuum sealer. All of these things are capital goods that are extremely useful but might spend a lot of their time used infrequently. Since these are going to be available to use a lot of the time I'm happy to lend them to a neighbor so long as I know they are going to come back to me in the same condition as they were lent. I just want a system where I can write down my expectations insofar as how I expect my things to be cared for and cleaned before returned, and how I can remedy issues and leave feedback like "3-stars b/c my stock pot came back dirty" or "5 stars b/c my stock pot came back cleaner than it was when I leant it".