It's hard to explain thoroughly, but Emacs is basically doing exactly what you say, except interactively. Instead of typing up an entire command pipeline all a

It's hard to explain thoroughly, but Emacs is basically doing exactly what you say, except interactively. Instead of typing up an entire command pipeline all at once, or running sections of the pipeline into temporary files that you examine/edit with a text editor, Emacs lets you run that same pipeline interactively in a text buffer (basically a temporary file). Being able to see the results as you work on it interactively is a huge advantage (compare ed vs vi).