Earlier quoted context omitted.
There are things like refactoring which technically are supported by vim extensions, but are just utterly inferior to the dedicated IDEs. For example - you know "extract method" refactoring. Pretty basic thing and I assume vim can do that. But on top of that when you extract the method, Intellij will go through rest of your code and try to figure out if some other parts could be automatically refactored to use this n…
That sounds very useful and it's not something that vim gives you out of the box but I'm not sure that anything you're describing is not possible via LSP plugins and extensions. Running a server to automatically search for duplicate code sounds exactly like the kind of task that LSP can handle. Since VSCode has tools for deep flow analysis (although I can't say how they compare to Intellij) then I'm pretty sure I can…
Another thing is the level of integration. There are many tools which offer static analysis, duplicate detection etc. But it's completely different level of usability when you see this info immediately as you type.