If you actually try to understand what's happening, I think it's one of the best ways to learn how a system is composed, at least if you install manually. What's a partition, file system, what does mounting do, chroots, you name it.
I don't use Arch anymore but still think it's a great distro to learn the basics while still having the luxury of new binary packages. Manual Arch install abstracts basically nothing away from you, for better or for worse.
Currently on NixOS, I'd say while its engineering is better overall, the things you learn there are much more distribution-specific or maybe concept-specific and often not applicable to other distributions.
I guess there are also probably ways to install e.g. Debian manually, I've never seen instructions for it though as there was always the focus on the installer, and frankly I'm not a big fan of apt and all. It always seemed to be much more convoluted than pacman plus it does a lot of stuff for you, whether you want it or not was my impression.