It'll provide similar benefits as writing your own text editor (which was suggested here).
It can also provide type hints and type checks for dynamically typed languages, thereby making them more like statically typed languages (also suggested in here).
Plus a good IDE will speed up searching as well as index the source code to make things click-able, thereby making large code bases or dependencies easier to navigate (also suggested in here).
So basically you can get a large chunk of the improvements that others have suggested in this thread simply by purchasing a good IDE :)
For a number of years I used the jetbrains IDE's (at alternating times I used phpstorm, webstorm and intellij), commonly perceived as best in class. Then I switched employers to a place that had standardized on VS code, so I moved over as well.
I have to say that while it was hard to get used to in the beginning, it is surprising how good VS code is. I get 80% of the featureset of jetbrains' products, for free. Specifically, all of the features you mentioned VS code does just as well when doing web dev.
The only thing I'm missing is the framework-specific automation helping you easily set up projects, builds, unit tests, and so on. VS code can automate those things, but there is more googling involved.
I think I've tried most java ides and they all suffer from the same issue which is that they're slow, unwieldy, and the benifit they bring (apart from debugging) are mostly not benifit at all. Learning how to write correct code without and IDE auto fixing everything you get wrong with a right click has been very valuable to me. Learning my build tool outside of crappy IDE integration has been an education too. Basically getting rid of my IDE has made me a MUCH better developer although I admit they do powerful and useful things.
It'll provide similar benefits as writing your own text editor (which was suggested here).
It can also provide type hints and type checks for dynamically typed languages, thereby making them more like statically typed languages (also suggested in here).
Plus a good IDE will speed up searching as well as index the source code to make things click-able, thereby making large code bases or dependencies easier to navigate (also suggested in here).
So basically you can get a large chunk of the improvements that others have suggested in this thread simply by purchasing a good IDE :)