Sure, but I wasn't making a unicorn pitch. My point is that IntelliJ's relatively deep code insight nudges things in that direction right now, to an extent that

Sure, but I wasn't making a unicorn pitch. My point is that IntelliJ's relatively deep code insight nudges things in that direction right now, to an extent that makes coding in traditional editors (emacs being my favourite of these) feel a little primitive. In emacs, to change a function signature, I operate on lines of text, often across multiple files. In IntelliJ, I work on the level of the function signature, and only incidentally interact with it as 'text'. This is partial and patchy at best, but IMO a move in the right direction (towards affording higher levels of cognitive chunking when coding). Some languages have elements of this kind of thing working with traditional editors (eg Go Doctor for golang), and I'd ultimately prefer this less monolithic approach, but it's not really there yet.