As pointed out already, LFS is a cookbook, and you learn most by having an idea about how you want to tune your Linux system.

So at points you want to dive deeper, you do — and go off the beaten path.

It requires a desire not just to understand how bits and pieces fit together, but how you can make them work even better for yourself and what is and is not customizable?

Arguably, even if building it today is easier — back when I did it in 2000, you sometimes struggled to find where the canonical source code of the package is, not to mention compilation errors, linking errors, etc. Only then did you get to configuring the init RC system, choosing between them (no systemd yet), etc.

But a requirement is — IMO — that you are strongly opinionated about how a system should serve you, and look for opportunities to tune it.