I see what you're saying, but I have to say as someone who was there, this was not the problem with Reddit. Early Reddit (as in first year) was extremely tech/programming/"netizen" focused, and it was really a lot like HN has been for years.

But when you start to gain popularity, the way you treat "free speech" becomes an issue. Discord is not a great example in that niche communities are not scraped for web search (that I know of).