what is stackoverflows mission statement?

While I am a Stack Overflow(SO) user, sometimes I am confused as to the need SO is trying to fill.

In the website's mission statement it says this: https://stackoverflow.co/

Stack Overflow helps people find the answers they need, when they need them. We're best known for our public Q&A platform that over 100 million people visit every month to ask questions, learn, and share technical knowledge.

However, SO has a community that feels fractured on the meaning of SO's mission statement between at least 2 groups.

IMO, this is because their mission statement diverges from their actual mission in big way:

1. SO is not simply a public Q&A platform, it is one that enforces the highest quality of questions and answers. Utopian SO would be equivalent to 1 perfect answer for every question. This means that you're not supposed to ask duplicate questions, questions that could be conceived as a duplicate question or questions that one or more questions as a whole could be construed a duplicate of yours.

There are many ramifications as a result of (1) above.

1. Only one user is able to own that answer and one user can own the question.
2. Don't expect to be able to help anyone in an area that are already covered with Q&A. You may be an expert in one or many areas, but SO may already have all the knowledge you have to offer. Even if you do find someone who needs help in one of these areas of expertise, they have asked a duplicate question which is frowned upon and will be closed as a duplicate.
3. Users are expected to do research before asking a question to ensure they do not create a duplicate question.
4. SO needs a way to moderate its content to prevent duplicates.

Some have described the SO community as 'negative' and 'anti-community'. For reference see: Why is Stack Overflow so negative of late?I believe these are symptoms of SO's unclear mission.

While this is a matter of opinion, it should raise questions:

"Is SO accomplishing its purpose?"

"Is SO's purpose too general?"

"Is SO's purpose and vision communicated and shared with its users clearly?"

SO still manages to succeed to a large degree in helping many people all over the world find answers to questions, but it is overly simplistic in its claim to be a 'public Q&A site'. Would it have a more positive community if it communicated its mission with its users more clearly?

The other option is to embrace all factions of the community by minimizing the harm that they can do to each other.

I would like to see improvements in at least the following 3 areas. These are low hanging fruit and should make a huge difference:

1. Closing questions as duplicates without enough justification or due process. I've had a question closed almost immediately as a duplicate which I could find no answer on, almost as if it was done automatically. No feedback, nothing. There needs to be a fair process.
2. Only reputation matters, and reputation is not easy to build. I've used this account for years, but still can't comment on other peoples questions. I'm not malicious. I've answered questions without votes. I've asked questions without votes.
3. Downvoting is tied to reputation. Why? Shouldn't upvotes and downvotes reflect the fitness of an answer or question rather than a user? Why not create a report-user feature instead to lower reputation and prevent malicious users?

With how long SO has been around, it's hard to imagine these ideas are new. What's the deal? Is this not possible? Maybe users would be pacified just knowing why SO has not or cannot do these things.