Yes I also did this years ago. During that time I was actually also fascinated by the idea of building my own OS - which I never did though. But if you do this,

Yes I also did this years ago. During that time I was actually also fascinated by the idea of building my own OS - which I never did though. But if you do this, you really understand how "GNU Linux" works end-to-end and stumble over a lot of interesting things with the upside of having a system tailored to your setup. I started using Linux when it was still necessary to compile your own Kernel to support literally anything going beyond the absolute base setup. The most difficult parts were bootstrapping the system and getting the glibc stuff right. The rest is indeed rather robotic, although I think there is some kind of package manager now included.