Somethings I find more convenient with Emacs than modern IDEs:

-Remote file editing with Tramp: This is much better even than using vi/pick over a terminal.

-Very flexible kill ring copy paste mechanism: can do complicated text manipulations with easy access to copy paste history.

-Easy macro recording and playback.

-Very flexible windowing: can show even multiple windows with the same file, even synchronized scrolling of required.

-Rectangular/column edits.

-Built in file manager.

-Built in shell, can run shell programs and capture their output.