It saves real time if you write your code the way IntelliJ wants you to write your code.

If you structure things differently - say, by steering clear of subclass inheritance, or keeping interfaces small, or not using the Bean pattern, then you can pretty quickly discover that there aren't all that many IDE refactorings that you actually use.

At this point, most the refactorings and code actions that I'm actually using exist in vscode as well; IntelliJ's main advantage is that I'm (somewhat) more able to use them efficiently without taking my hands off the keyboard.

They’re immensely useful tools when working in large poorly-structured codebases, and they are more than worth it when dealing with stuff like that.

Extract interface, implement interface, extract method, move(to own file) only exist for go and c# via jet rains and are practical for anyone writing real world code.

Visual Studio does at least some of those for C#.

And vscode has them for Typescript at the least, I suspect several other languages support them.

VSCode C# extension supports all of those.