> Maybe it’s just me but the instructions seemed to focus too much on what to do and not nearly enough on why. I came out of it thinking that I learned much less than I expected.

In the "good old days" it was recommended to install the linux-howtos package and there was one howto https://tldp.org/HOWTO/From-PowerUp-To-Bash-Prompt-HOWTO.htm... which explained the boot process. There are also other howtos who talk about X.

Nowadays with systemd and the (stupid) tendency of using a lot of shared libraries the things have become more complicated.