Earlier quoted context omitted.
C# also has always been done like this, but 20 years ago only Microsoft could pull that off.
C# emerged around the time that Java IDEs emerged. Basically, MS did a decent job with the C# language and tooling. However, it was very much inspired by Java, Java IDEs and Microsoft's own Java IDE (Visual J++). I think IBM was first with supporting refactorings for Java in Visual Age and Eclipse. Refactorings themselves emerged out of the Smalltalk community. MS was very motivated to support that for C# as they wer…
Microsoft intellisense (aka code completion) was truly a first back in 1997 (then just for VB and C++).