Anyone looking to pick this up: I found the best way to consume it is to grab a couple tips at a time (it’s structured as a “recipe book”) and incorporate them into your workflow. For example, try Netrw for a week, then another week try out folds. You don’t have to read it cover to cover to get the full benefit of it.
This is exactly what I'll be doing with these articles for the next few weeks. Learning a few cmomands at a time gives them time to sink in and become habit.
Drew Neil's Modern Vim is also wonderful. While it introduces a lot of plugins in an attempt to modernize the experience, it also includes some excellent notes on standard features(qf/sessions/etc).
I'll also note it covers both vim and neovim, with nice little asides explaining the differences where they matter.
I took Drew's Vim Masterclass with some coworkers years ago. I considered myself a fairly advanced Vim user at the time, and still learned some handy things during his class. It was a small group (we hired him just for our group of coworkers), and he took time to answer everyone's questions. He's got a great teaching style. I'm not sure if he still does the class, but if so, I recommend it for all Vim users.
In some ways it's quite conceptual about the best way to use vim. Inside the cover there's a quote "I thought I knew vim, but practical vim has massively improved my code-wrangling productivity".