Are Debian APT packages not officially supported or acknowledged by application developers?

I want to understand how the APT package is managed in general, considering the following situation I got into today: I was trying to add MongoDB to my Debian machine. apt search mongodb showed good-looking results, and before attempting to install I read the [MondoDB documentation](https://docs.mongodb.com/manual/tutorial/install-mongodb-on-debian/) which stated: >Follow these steps to run MongoDB Community Edition on your system. These instructions assume that you are using the official mongodb-org package -- not the unofficial mongodb package provided by Debian -- and are using the default settings. From this, I understood and was surprised that what I get from Debian's apt install is *unofficial* by the developers of the app. This sounds worse than "not recommended". I do understand Debian APT package repository tends to show old versions and is never meant to catch up with latest leading edge updates. There are so many ways to deal with this, but now I'm concerned by the words *unofficial*. Does this mean, packages related to MongoDB (or any other app) on the APT repository isn't officially approved by the app developers? Or was it officially shipped by the developers but "avoid because it's not the latest version"? Or did someone (some entity?) copy from the official installation package and paste it to APT? I'm not trying to understand just this specific case with MongoDB. Instead I want to understand the overall "politics" on applications and APT. How does it work, how was it supposed to work? If this is a noob question then I'm sorry, but I couldn't find a good explanation online. Any links or reference would be appreciated.