I've skimmed the guides. They never contain anything useful. They're just a bunch of recipes. They don't actually document a darned thing.
Programming is not regurgitating recipes without understanding. Copilot can do that. Programming is actually understanding both the problem domain and the solution space, and knowing how to find some permutation of elements in the solution space to address anything in the problem domain.
The rails guides document about 10% of the problem domain. That's mostly ok, because the problem domain exists in the wider world, and there's lots of documentation elsewhere. The problem is that the rails guides document about 1% of the solution space. And that's an issue, because rails claims to be the solution space.
Rails routing is done by passing a block into the framework that's instance_exec'd on... Something. Want to know what, so that you know what API is available to you? Too bad. Here are a list of recipes for the couple most common things you might want to do. Want to do anything more sophisticated, or just understand what your options are? Uh, sorry.
Oh, you want to set and read cookies? Here's a recipe for how to read cookies and how to set them with lots of options. You changed how you're setting cookies and now browsers are returning two cookies of the same name and you want to know how to detect and fix this? Silence from the rails guides! (In fairness, the rack documentation actually included enough information to solve that. But it wasn't mentioned in the rails guides about cookie handling. And the rack documentation was a specification, not a guide. It actually tells you what pieces there are and describes their semantics.)
And it just goes on and on. Rails has about one hundred options for every one actually mentioned in the guides. In some sense that's a good thing. The guides only give you an incredibly limited set of tools. It's very good that the rest exist. But it means that the guides are a very bad way to learn rails, because they don't give you enough information to solve unforeseen problems yourself, or even enough information to understand code someone else wrote to solve those issues.
They put you in the position of hoping someone else anticipated your weird problem and already told you how to solve it. They don't equip you for solving anything weird by yourself.