What's happening is that the bigger communities that are just about a topic but not really a tribe or wealth of useful data (think r/funny or r/pics) stick around.
And individual users are deleting or editing their comments before they close their user accounts. So a lot of the good info that used to be on reddit - that made reddit valuable - is leaving.
I'd like to see a search engine that has a setting to just search forums. Organic user generated content is where most of the valuable information is, at least for troubleshooting/ product recommendations/ hobbies.
It's crazy how badly google fucked up the internet with their shitty SEO rules. I can't find what I'm looking for half the time because I need to sort through a ton of bullshit once I get passed the ads.