NixOS is still a Linux system, and the configuration still translates to stuff you have in a very similar way on every other Linux system too (with the exception of what's needed for the file system layout to work). It's not some kind of magic. I've probably learned as much stuff applicable to general Linux distributions as while using Arch and Gentoo.
Of course, if you only use the high-level options and the graphical installer that may be different, but then comparing it to those distros is very disingenuous.
Mhm. The exact same reason why I would recommend them to anyone that actually
wants to know how Linux works, the dos and donts (like why having 2 or more package managers is a REALLY REALLY bad idea).
No, just a bad experience trying to actually run 2 of them on the same system. One was the main, the other was supposed to "patch" what the first one lacked... and then I realized that compiling from source and packaging with the original (first) package manager is a lot less painful than trying to juggle with both of them.
Well, you just set the second to ignore all inconsistencies regarding libraries and binaries from the first one. It sounds easier than it is to actually put in practice 😂.
I was just experimenting, trying to see if the trouble is worth it... it's not. Way too many ways to still fuck up your system... and I eventually did 😂. Luckily, I use BTRFS with snapshots, so no harm no foul, I just rolled back everything from the day before I decided to install the second package manager.