Yes, it’s extremely frustrating that Webpacker and Rails never quite agreed on file structure, and that Webpacker is continuing to make changes after the book came out.
Webpacker still hasn’t released an official 6.0 version, and Rails 7.0 changes everything all over again.
I’m not quite sure what the most useful thing to do about this, but creating a good place to go for current instructions on setting up the app is probably useful. I’m not sure whether it’s worth doing a Rails 6 one, or doing a Rails 7 one, or both.