No, I don't need or use all the IDE features. I don't use the integrated shell, I don't use the git integration, I don't have it handle my packages. I don't see a need for these things when I always have multiple terminals open anyways, but proper code intelligence is not something an editor+plugins can provide like a real IDE can.
I don't care at all if someone prefers IntelliJ over Emacs (that's a pure matter of taste) but the idea that it's impossible for an editing environment that isn't delivered as a single, integrated monolith to expose powerful language-specific tools such as interactive lints, large scale refactorings, debuggers (check out DAP for the debugging equivalent of LSP), etc was never true as a technical matter and is increasingly untrue in the real world.
One of the best developments in dev tooling in recent years is that it is starting to be seen as the norm for new languages to provide canonical language server implementations. Long may that trend continue.
What makes LSP not 'integrated' in the sense of the I in IDE is the fact that it is decoupled from the editor, allowing one editor to work with many language servers and one language server to work with many editors.
Seems like you haven't used VSCode in a long time. It is my primary everyday editor for Typescript, and it has all of those things you listed: I can move a class to a separate file in one click, code completion always follows type system, it is aware of all packages that I have in package.json and offers to import them, and so on.
The IDE/editor distinction really doesn't have as much meaning as it once did.
My biggest problem with vscode is lack of UI configuration. You can have only one panel which is huge waste on big screen. Some useful features compete for screen space (outline vs. project explorer, project explorer vs. debug window etc.). This makes me way less productive than using heavyweight configurable IDE.
I've tried it for more serious development for Rust, Python, and TypeScript. While for Typescript the inference is barely acceptable it complete sucks for Rust/Python.
But the thing is this is all hypothetical - it is possible if somebody invests those thousands of hours into it. But so far it did not happen for most languages and Intellij IDEs are still vastly superior to VSCode for e.g. Java, Python or C++ development.
My guess is that was intended as hyperbole, like saying you think they are "crazy" for doing so. Still, I'm thinking you'd be more likely to get interesting feedback by stepping it down a bit.
I find it incredibly pompous that you believe that people who have been writing C++/C even Java for decades in editors like Emacs, Vim or even Sublime don't know what they are doing. The IDE vs Editor argument is nearly as old as Emacs vs Vim.
As a personal anecdote, I've seen people switch from vi to IDEA after a pair programming session. In that session they learned that IDEA has full understanding of the frameworks, configurations, code annotations and bindings etc. that we used in a project, and that you don't need to spend 15 minutes furiously searching in files for stuff when you have to change something in two or more places.
It's absolute pain to write Rust/Java/C++ in any of those. No safe refactorings (moving classes? good luck), completely random code completion, 0 awares of available libs/SDKs, and so on.
It would seem that most of the developers have no clue what's the difference between a lightweight editor and a full-featured IDE. I think it's just Dunning–Kruger effect on a scale.
I understand that I'll be voted down into oblivion but it really rubs me the wrong way when people confuse some kind of server/application server (???) integrations with an IDE that can offer sophisticated refactorings, a proper type inference, and can infer which functions from which lib/SDK I am using.