Refactoring in IDEA also allow you to for example also change function signature, safely delete an element (class, function etc.) - i.e. with full impact analysis, move code, extract interface/trait out of a class.

I've tried the ctags-indexes with Sublime and afair the basic navigation was not bad (I think I remember there being an issue with some delay though? It was a while ago). I'm not sure if things like "show code which access this variable" or "show all children of this class" are supported though?

Apart from those advantanges, I can think of two more:

1. IDE can import your build file (maven, sbt or bazel project for example), parse out the project structure from it and download the necessary dependencies. I don't think that ctags-like powered solution is as robust, which means you'd have to fiddle with it until it can understand the structure a complex repo.

2. IDE can run and show the results of unit tests. (just right-click on test you want and select "Run" from context menu).

My build tool spat out a 700MB compile_commands.json file, which the C++ language server turned into 25k files. None of the language server implementations were able to process even a go to file on the code.

it takes about 15 minutes for Visual Studio (well, visual assist) to generate the index for the project, and then the navigation is instant. I've tried a few times over the last few years with various language server and clients, and my experience has been the same pretty much every time.

You can use ctags/cscope to handle that, FWIW languages like C and C++ have a massive toolset built around Vim, so even for the most obscure use case, I'm pretty sure there will be a way.