I can understand zip, 7z, and tar. But RAR? My only experience with RAR files comes from malware and warez (illegally distributed software, often compromised). Perhaps my own experience is just biased.
You are most likely biased. I use RAR for most of my own larger archives, even on Linux (i use WinRAR via Wine - and yes i bought WinRAR some years ago :-P), mainly because its compression is much faster with comparable results to something like 7z/txz/etc.
I use rar for backups as well. Its superpower is recovery records. Reading bytes off a hard disk doesn't always work the same years later. I have seen corruption on hdds.
Also use it to span backups across multiple archival M-Disc blurays.
I also prefer the UI and configurable dictionary size to 7zip. Rar lets you isolate each file if you wish instead of solid compression. Ever had to insert 2 blurays just to get a 3kb text file out of an archive?
I guess it depends on your region. In Eastern Europe, RAR seems to be more popular than ZIP (that's why, I think, you mostly saw it on warez sites because they are often managed by East Europeans)
So long as it's just extraction that's cool. There will always be old data around and not having to install a third party app to extract it then I can't see a problem. Allowing extraction doesn't encourage anyone to create more rar archives.
But yes, the only people who use it these days are the people who started using it long ago and just never switched.
Safely letting users easily see what's in a suspicious RAR before just blindly extracting it or opening it in third party software (possibly with known/unknown exploits) sounds like a good security feature for an OS.
Rar used to be the option of choice when you had file upload size limits, then you could use multivolume.
7z does this now, so it is legacy stuff I come across I use RAR for. I am not aware of any advantage for RAR over 7z. I rarely have to use multivolume these days anyways.
I was thinking about this when it was announced and I wonder if the motivation was somewhere else at Microsoft to scan these archives for malware on their cloud platform and someone just hacked the code to run on desktop windows or if it came along for the ride when Microsoft was intending Win11 to be an android killer for phones.
If you have many friends that are windows power users, there's a high chance they'll use rar if they ever have files to send you. This may be indicative of their cultural familiarity with the warez scene, but they use it for anything. I've received rars from people of their own music, photos, projects, etc.
A long time ago RAR offered the best compression(lowest archive size) in a free(*endless trial) tool compared to other formats. I think only bzip2 in Linux offered a similar level of compression.
RAR is great for long-term archiving without any additional tools. You can add recovery records, and even create recovery files (think parity / PAR files) all in one go.
I wouldn't know what to do with a RAR file on a Linux machine, and I've used Linux for over 20 years (and Unix before that? Don't even ask, youngster.) I mean, yeah, I'd figure it out; but I've not had the need.
As sibling commenters said, you're probably thinking of .tar. Now that I run into a lot. :-)
I probably installed it many years ago from the repositories. Now that linux gaming is so good I've been seeing 7z and rar being used for game mods a lot.
What? In my experience, RAR is extremely un-Linux. It's not free software and not command-line friendly, and it seems mostly to be used by piracy weirdoes who need to split up files for uploading to newsgroups.
If you're on Linux, you make .tar.gz or .tar.bz2 or something. Or .zip, I guess you see sometimes. But RAR? That's a windows people thing, in my experience.
Though i rarely distribute stuff in RAR.