My gauge is how predictable it is - I can predict how a Reddit thread will go 90% of the time it seems, maybe even a 4chan thread 80% of the time.
The value of a community is in the unpredictability and HN has a good percentage of that, and I can choose to ignore the threads that will be predictable (though it can be fun to read them sometimes).
>>bombca+(OP)
That’s mostly the default subs tho, like worldnews, funny and so on. The first three comments are whatever the previous three comments where in the previous thread on the same topic. Subs like r/askhistorians has a brutal moderation where the only parent comments are well sourced informed ones.