Slackware wasn't the first Linux distro, but it's the oldest still alive and kicking
(www.theregister.com)
When I started playing around with Linux 25 years ago Debian and APT was a small revolution in how good it worked out of the box.
I tried to get into Red hat and SUSE and I always wanted up in trouble even before I got any Windows manager up and running. Don't get me started on RPM and dependency hell
Debian just worked. I had stuff up n running BEFORE I had to go down the rabbit hole to understand how all things was connected.
For a beginner that was a game changer.