This works on platforms like HN, Less Wrong or niche subreddits, which

i) work on the reddit model (submissions + tree of comments on them) ii) are heavily moderated (e.g. no memes but also specific restrictions like on a book series subreddit to not discuss the movie adaptations)

Then this vote-based ranking makes cream rise to the top, I agree.

In general, your "depending on how best is defined in the given context" does a lot of heavy lifting.