Neighbors in the sense of projects you use, depend on or interact with in your project.
It makes sense and is in your own interest to assist with the projects you use and need so that they can flourish and improve in ways that by extension makes your project better or easier to develop etc.
Your project cannot succeed and become that bright north star on the sky you want it to be, unless it can be carried forward and upward to that position by good tools and fine dependencies. You should seriously consider being a good citizen and a contributor to your neighbor projects.
If you are fortunate, those other projects do perfectly good without your help. You can still benefit from keeping an eye on the most important of your neighbors to see what happens there, to realize when you need to adapt to changes, when you can help them with your feedback or when you can submit your opinion on design choices they need to do.