Can you give 5 features of such IDEs which aren't found in IntelliJ?
2 - No continuous indexing of source code, stuff is just there.
3 - During execution of REPL statements or debug sessions, an errors jump into the debugger, fix the issue and continue as if nothing had happened
4 - a REPL that integrates the code being written, with inline images and graphical representation of data structures
5 - The complete developer experience is available to the developer and can be customised at any time without rebooting it.
6 - Code components can be integrated into other documents as live objects (this is where OLE and Taligent got their ideas from)
I do think that the REPL workflow is way underappreciated and missing in Intellij. What I like about it is that it still focuses on working on semantic intent rather than editing text. In this way, it's similar in some sense to the idea of working on S-expressions rather than text.
After all I was asked for 5 and wrote 6, could keeping writing a few more.