Rar has become one of my hot-buttons, so I'll respond as a consumer of compressed files in general:

Multi-file volumes are good and useful for many things, but last I checked, RAR doesn't offer a compelling advantage in performance, compression, or error correction vs. more readily available encodings, yet is encumbered to boot. (Feel free to correct me, if that is not factual).

Not that pirates probably care very much about that, and backwards-compatibility with old practices is always a consideration, but every time I see someone distributing software in a rar (not even pirated, mind you!) I always sigh deeply. It seldom happens, but...sometimes...

You rarely see scene related products (content/software) distributed in rar format? Really?

I refer to compressed artifacts in general, here. I do not consume "scene" artifacts. I am merely positing that there is no technical reason for the choice in this era. But having lived through the last one, I can understand why it became common then.

RAR isn't used for compression. The archives offer checksumming and splitting, but they shouldn't be compressed. That subset of the RAR format is unencumbered.

> last I checked, RAR doesn't offer a compelling advantage in performance, compression, or error correction

May be time to check again:

http://www.quickpar.org.uk/AboutPAR2.htm

RAR != PAR. You could apply PAR2s to any format, even (gasp) a single file.

We do. Our tools use it to help customers in India upload multi gigabyte movies to our storage in the US.

But nobody uses RAR without PAR2, and I was responding to the bewilderment at those using RAR.