Compared to old VS: First and foremost: feature richness of refactorings, code inspections and plugins - basically in the IntelliJ you have everything Reharper plugin can do for .NET and probably more. Second IntelliJ can run on non-spying operating systems. Third it's much more resource friendly for bigger projects. Last but not least ItelliJ is keyboard user friendly (e.g. you can jump and resize windows using only keyboard).
Can't say much about vscode vs IntelliJ. When I tried it last time Java plugin was not there. I could not use ItelliJ keyboard shortcuts - also code formatting and refactoring options were worse than in the itelliJ. That's to be expected it's paid product after all.
vscode is basically a bunch of different tools duct taped together and, as a result, constantly breaks. It's a lot closer to being emacs than it is to being an IDE (and I say this as a fervent emacs user outside of large projects). Even with the language servers, IDE functionality is going to be playing catch-up for the next decade. Intellij definitely has a leg up there.
I've never used visual studio before so I assume the comparison is going to turn up a different set of issues. However, being tied to windows is probably not a good thing in the long term.
Compared to old VS: First and foremost: feature richness of refactorings, code inspections and plugins - basically in the IntelliJ you have everything Reharper plugin can do for .NET and probably more. Second IntelliJ can run on non-spying operating systems. Third it's much more resource friendly for bigger projects. Last but not least ItelliJ is keyboard user friendly (e.g. you can jump and resize windows using only keyboard).
Can't say much about vscode vs IntelliJ. When I tried it last time Java plugin was not there. I could not use ItelliJ keyboard shortcuts - also code formatting and refactoring options were worse than in the itelliJ. That's to be expected it's paid product after all.