My Kali Linux version: Linux 5.9.0-kali5-amd64 #1 SMP Debian 5.9.15-1kali1 (2020-12-18)
I'm fairly new to Kali Linux and for the past month I have decided to introduce to myself this fascinating distribution. I have read this book: https://kali.training/topic/preface/

But there is one particular issue that I couldn't seem to puzzle out, many important configuration files (those ending with the .d suffix) were empty.
Real life examples are the network interfaces(5) /etc/network/interfaces.d/ and apt preferences folder /etc/apt/preferences.d/

I have been searching for days the reason why these particular directories were empty on my machine.
So far I have upgraded all my packages and Kali to the latest version, also there is no issue with the directories' permissions

ls -la command:
drwxr-xr-x 2 root root 4096 Jul 8 09:38 preferences.d

also:
source /etc/network/interfaces.d/*
bash: /etc/network/interfaces.d/*: No such file or directory

Can anyone help me to understand why these .d directories are empty?




Note: This is my first question and I would like to sincerely apologize for any possible lack of details on my problem, so if you need additional information I would gladly present it to you