This is so sad and bad. This was the one site that had built-in mediainfo for all uploads. You could tell at a glance what was garbage and what wasn't with a fair degree of certainty. They also were as a result an informal chapters database for movies (plex still maintains a chapters db but they closed it to new submissions in like 2015/2016 or so, so rarbg had chapters for newer movies if the release you got didn't include them).

They were also not only an incredible source of scene releases but also last resort stuff. There are incredibly rare movies, tv shows that they had their budget-sized encodes of (better than yify/yts which is just intolerably bad looking) which were seeded which you couldn't find elsewhere outside of very elite private trackers. If you wanted full season packs of some old not so popular TV show from decades ago, rarbg was the only place you could find it (eztv has some stuff but nowhere near as much and I dislike them for the way they pollute and spam api searches in qbittorrent by returning irrelevant random results when there are no real hits on their site when using movie searaching).

By comparison 1337x is at least a tenth if not a hundredth the size in terms of meaningful content (lots of garbage by bad encoders, encoders who I don't trust not to insert a big burned in "encoded by asshole, visit my spam and malware friends at totallysafesite dot ua"). With rarbg you could count on having subtitles available 99% of the time. You could count on reasonably well done encodes without visible artifacting except upon frame-by-frame analysis. You could count on direct scene releases from known groups as well as their own. They had amiable stuff, NTB webrips, sparks, many others. It was all curated. You wouldn't find bad encodes or encodes with text spam in them there.

Now, for a lot of things the only option left on only lower tier (/r/opensignups stuff) private trackers is downloading full BD rips and remuxes and re-encoding at enormous expense of time, cpu cycles, heat, etc. For TV shows this is quite an ask as a season alone could easily be over a hundred GB, a full show (and private trackers usually have rules that mean you either have to download the whole thing and seed for a week or seed forever in a vain hope of reaching 1:1 on a partial) could be a terabyte.

Regarding alternatives:

piratebay is pretty much useless for anything but ancient collection torrents IMO. I mean sure people upload stuff but it seems to only be stuff that's already been uploaded in better places previously. That plus the lack of vetting, malware torrents for software. Generally seems recommended against in most of the piracy scene for anything but last resort. You won't find good scene releases there or good stuff from quality release groups (unless someone uploaded it as a one-off), won't find scene stuff with any frequency, there are no native release groups there of any notable quality that I'm aware of.

torrents-csv.ml though an incredible project is just a mirror. No new torrents can be uploaded there. And it doesn't contain a place for comments or media info (you have to actually open the magnet link or torrent to see the files and download them for mediainfo running against them). So while that's useful and I'm definitely thankful to the person behind it as in moments like this it's invaluable, it also has severe limits and if other sites collapsed it would be no replacement.

I'd say the last standing truly good public sites with any variety are 1337x dot to and rutracker dot org. Admittedly rutracker is semi-private but anyone can get the magnet links without signup and you can sign up easily enough not knowing Russian using translation tools. (Use jackett with a rutracker account so you never have to log in and deal with reading around in russian to actually get content)

1337x's content is also mirrored or re-uploaded on limetorrents (website looks odd, kind of sucks), kickasstorrents (just people leaching off the name sadly but a nice mirror and tracker announcer at least), torlock (no idea, website not as nice as leetx).

However leetx has frequent outages, frequently doesn't even respond to api queries via jackett and with the death of UTR years ago has only one major release group (QxR) left along with a few dedicated quality releasers who release stuff on a very small scale and infrequently. Additionally it has no requirements for mediainfo which means you have no idea what you're getting with many of the uploaders. Maybe it's some crappy encode with italian and no english track. Maybe it lacks subtitles.

And QxR doesn't do releases of TV shows except when the season is up and they only do a small number of those compared to the amount of new content produced, a totally inadequate replacement (1/1000th of rarbg TV content easily). I know that for example rips of streaming shows, the latest episodes always hit rarbg first. I'm not even convinced that the uploads on other sites like leetx weren't just people downloading those then re-uploading or at least using them as a source, quickly re-encoding at crap quality and then uploading.

This all said, if you're reeling from this, do look into entry private trackers /r/opensignups. You will have to wait a while. Most trackers do open up around Christmas/New Years, TL just had an invite give-away for spring which expired (though with rarbg vanishing they may do some sign-ups soon, hard to say). You do need to check daily or every other day as slots can fill up quickly and sometimes openings are only 48 hours. Beware private trackers have rules and it is very easy to get banned if you do not thoroughly read and understand them. If you don't have a machine that can seed for 12 out of 24 hours a day or more and can't buy a seedbox you probably won't be able to stay on most of them.