Up until 2016 (I think, +/- 1 year), if you could remember 3 uncommon words in a comment, you could find any reddit post instantly on Google. I'd want to follow up on a thread from weeks ago, and it was magic. Number one result. Then one day that just stopped working, and even adding site:*.reddit.com didn't fix it. At the time, I think, I didn't realize that it was mostly Google's fault, I thought maybe Reddit had changed their infrastructure so that it couldn't be crawled properly.

Google hasn't been a search engine in a long while, it's just an advertisement engine now.