Linux

The thrilling thing about arch is you get to put together your own user land applications, especially things that could form your desktop environment, audio stuff, etc.

I agree it is not that complicated. If you want more thrill, here is what I recommend:

gentoo Linux

has the option to compile everything from source. This isn't just for bragging rights. This resolves a whole class of software breakages that can happen on other distros (especially when using old or less common applications).

• It gives you the option (emphasis on optional) to use openRC, an alternative to systemd.
• patch any software super easily, working nicely with the system
• customize compile flags on a global level
• have package manager manage software that isn't available in repos, or easily write a package script for it (technically AUR can do this, but gentoo more powerful)
• works like a charm with heavily customized setups, such as musl, or less common architectures like arm or risc-V

NixOS

Takes it a step beyond gentoo and uses a functional, lazy approach in package management. Every package is fully reproducible, has a kind of isolated environment. Your entire setup is reproducible and declared with a single file.

---- below this line is torture. Not recommended

slackware

Idk how it works exactly, but package management looks like a manual pain

Linux from scratch

A book where you create your Linux installation from scratch, compiling every single component until you reach a working system

Notable mentions

• Alpine Linux: uses musl and busybox by default. Extremely lightweight. Some things will not work, but you get the thrill of running a couple MB distro
• void Linux: ok I'm tired of writing so I will not explain that one