dired-mode is fairly necessary in emacs to preserve the continuity of what you are editing.

For example, if I'm editing a file called originalfilename.txt, and I decide it should be called newfilename.txt, I can mv originalfilename.txt newfilename.txt in the terminal and it's all good, but you're still editing the buffer originalfilename.txt in emacs and if you save it you will have a new file with that name.

Using dired to change the filename updates all the buffers that are using that file.

dired gets some hate, I think because it creates a lot of buffers and they tend to stick around, but it's never bothered me.