Gentoo I understand but Arch? Does Arch go into compilation that much?

Not so much compilation, but it does delve into system management in a way that other OSes don't. Arch has few defaults setup for the user, so if you do it from scratch you'll end up needing to go through several of the general setup recommendations [1].

That's where you end up learning a lot about linux which is particularly practical. Other Linux distros, especially for the desktop, hide a lot of this information behind nice guis.

[1] https://wiki.archlinux.org/title/General_recommendations