It is all apps. You can even disable sharing. Heck, you can disable the Files UI...
Note that most people use Nextcloud to work with others and features like these are crucial to their productivity. In the end, we're guided by community contributions and customer demand... Luckily you can disable things you don't like :D
Maybe all this will be optional, but the direction seems opposite to my needs. And the risks from 'extending' the network too.