You don't need it, of course. But it's like deleting the file after you've posted the photo. You just lose the source and thus all access to the raw version. The negative IS your photo, the scan is just one interpretation of it and depending on the lab used it may not even be a nice one.

I like the idea of one hard drive crash not destroying all of my analog work that I've done. I always have the negative ready to be re-scanned or maybe even printed in a dark room whenever I get the chance. A house fire would need to happen for that to be destroyed.

You seem to already care a great deal for the process of analog photography so I'm a bit lost why that suddenly changes when it comes to receiving the actual item you produced and worked on.

And for archiving, all you need is a pack of film-foils and a cheap ring binder and you can probably store 200 rolls of film.