I only assume the reader has basic command-line familiarity, but I try to make the writing approachable for both newer admins and veterans.
Right now I'm working on a chapter on security, and another on Roles, and will probably publish an updated version next week.
I'm also working on getting one or two really good technical editors, as right now I'm basically doing my own editing as I go, one chapter at a time. Once I feel comfortable with where the book is, I'll be publishing on Amazon so people can get a hard copy.
[1] https://servercheck.in/blog/self-publishing-my-first-technic...
If you didn't have a checklist, could you remember all the steps to get the machine back to its current state? If not, you probably should have a checklist. Chef/Anisble/Puppet lets you make such a checklist, but that checklist is actually runnable so that if you needed to bring up a new box it's just one command line away.
So, are you missing out? Maybe. It depends on how complicated your setup is. My experience is that over time, the complexity tends to go up. It seems like extra work up front to make all your configuration changes in some weird extra layer, but as your changes grow and grow it becomes nicer and nicer to have them all listed and documented.
An analogy: it's kind of like programming with no source control. You can do it, especially if you're not collaborating, but as time goes on it becomes more and more cumbersome to work without it.