Reddit has almost 20 years of comments.
You could certainly argue that it's less true now that there's legitimate people commenting, but there are years old threads on there with very helpful and valuable information that you can only really find via some incantations of Google search.
Have you ever looked at an old reddit comment thread.
Some of that was a reaction to Reddit closing the APIs and blocking apps.
Reddit will delete anything remotely controversial if it contains referenced facts. They banned and deleted my account for simply stating the 5th amendment prohibits requiring incriminating yourself to exercise a right. An Ivy League educated lawyer dug up the comment one year after I posted it, told reddit I was distributing illegal legal advice, and had my whole account nuked.
https://github.com/Tryhard-cs/reddit-download-tool
https://news.ycombinator.com/item?id=48951669
Treat Reddit as the temporary object storage system that it is.
Reddit HAD almost 20 years of comments, until about three years ago when they started to lock down APIs, remove moderators, and make poor choices. Users reacted accordingly and now you will just see a whole lot of [deleted] or comment content replaced with garbage data. It's no longer an archive or wealth of information it once was.
That redacted amount is absolutely miniscule and blown out of proportion.
More than 20 years
Put a fork in me, I'm done.