Before typewriters, authors wrote by hand (like, say, Charles Dickens).
Or they dictated (even later writers, such as Georges Simenon of the famous "Inspector Maigret" series, dictated to a secretary).
I wrote my first novel (unpublished, but available online here) on an electric Army Surplus typewriter.
It made a tremendous noise, like this: Hummmm... chakk-chakk-chakk KA-CHUNGG! Whizz... Chakk-chakk-chakk-chakk KA_CHUNGG!
(My neighbors must have hated it.)
And then came computers.
Have you noticed how long most novels are today? It's not just because publishers want them that way. (The strategy seems to be that if your books have thick spines they will visibly stand out from, and take shelf space from, competing books.)
The prime reason why books are so long today is that those evil, evil computers replaced typewriters. Suddenly, writers didn't have to think before they wrote. They could just pour out words and proofread on the fly, thanks to the Spellcheck function.
The computer-as-writing-tool makes us all self-indulgent. (I stand accused.) For instance, with a typewriter you would think twice before planting a three-page infodump in your manuscript. It forced the writer to be economic with words, to get to the point.
With a computer, it's so easy to show off every little irrelevant tidbit you dug up in research, you can't resist putting ALL of it in your manuscript.
So would I go back to using a typewriter?
Too much bother with the paper and noise and correction fluid and typing-arms getting stuck...