Unfortunately, the rule of no duplicate questions also destroyed lots of questions that weren't duplicates... because _someone_ couldn't be bothered to read them and realize it wasn't the same.
Plus, there were a lot of fun questions they were really interesting to start with; and they stopped allowing them.
Yes, this. I've asked a couple of questions where the only responses are from people saying "possible dupe of x" where x is something that has a couple of the same words but no relation to what I'm asking.
Turns out if you design a forum where a high effort, high quality post can be devalued by a low effort response, you discourage high effort, high quality posters.
This is where we need SO's "The Answer" feature, whatever they called it. Never seen it distilled so well.