Renaming a field or method of a class is more tricky with an editor, though, since other classes may have a field or method with the same name and you may not want to rename those.
It's also nice not to have to remember or look up APIs, constant names, etc.
As a teenager, I used Borland IDEs (mainly Turbo C). Then I spent over a decade mainly using commandline tools (C and assembly). But then since starting Android development some years ago, I've gotten to appreciate IDEs enough that now sometimes I even write LaTeX presentations and articles in Eclipse and short python scripts in Visual Studio. (If only loading time were faster.)
Over my decade of commandline development, I also forgot how helpful a GUI debugger can be and only rediscovered it recently.