Torrent search engines that crawl the DHT seem like they’d be the least likely to be taken down, as they don’t host any torrent files or run their own trackers, they simply crawl the torrent DHT directly for magnet links.

Here are my two favorite DHT-based torrent search engines:

• https://bitsearch.to
• https://btdig.com

The only way I could see things going south is if corporations start buying popular instances

It’s not quite the same, but Meta/Instagram is working on a Twitter competitor that will use ActivityPub and therefore is essentially one huge Fediverse instance that they’re launching.