Note that most of these are just regular people with close-to-vote powers, not elected or appointed moderators with special powers.
I think one major problem is that there is an entire class of people who rarely or never ask or answer questions, or even comment, and all they do is "moderate" the site by closing questions. Literally all they do. Some of these have extremely specific and narrow views on how the site "should" be. I absolutely hate it: who the hell are you? You're not even using the core function of the site. Fuck off trying to tell me how I "ought" to be using it. I don't want to gatekeep who is or isn't "part of the community", but people gatekeeping how the site can be used without actually using the site is just absolutely toxic.
There are a number of other issues as well. I can go on for a long time. But to be honest I no longer care: the site has been taken over by nihilistic capitalists who care not one iota about any aspect of the site other than the ability to earn a buck (previously it was a commercial enterprise as well, sure, but it wasn't 100% about earning a buck and many in leadership positions genuinely cared about "doing right by our community" as well). And that is probably just as much of a reason for the decline of Stack Overflow as anything else.
SO should do something similar. Throw out all the mods, all the questions and start fresh every X number of years. No idea if it will work but tossing out the current mods to bring in new ones would change the flow.
Also: Stack Overflow is intended to be a long-term useful repository of question and answers. You enter "how do I frob a baz in foo?" in $search_engine, and the idea is you'll end up on Stack Overflow which answers that exact question. I have sometimes ended up on some of my own answers from years ago like this.
The old answers can no longer be used as the basis for duplicates, a new one must be created ( that brings a slew of problems, such as sniping for getting magic points).
But the refresh of PEOPLE (mods) is where its needed the most.
What is wrong with duplicate questions though? If the response - yes but my use case is a tad different and its not covered by the linked solution, then dialogue should flow not restricted
You and I are talking about different things. Before these great questions and answers ended up in your search result, someone asked them, and someone else provided a good answer.
I used to be one of these people. I got 50k+ SO karma, mostly by asking good questions. I no longer bother, because SO moderators don't even read your questions anymore before closing them for a random reason. Needless to say, I no longer bother trying to answer questions as well.
So, it's no wonder that SO is struggling. You can't thrive forever on a stock of aging questions.