The short version: Stack Overflow was always, explicitly intended to be the site that you think "went wrong", and is made so by a community that actively discusses policy (and gives detailed reasoning) in the open - not by its tiny, overwhelmed moderation team. There is abundant historical documentation of this, but it took time for that intent to be explained coherently and the site initially grew far faster than it could be properly gatekept. This was aided by a broken and ill-conceived reputation system that never got the rethinking it needs, even after overall feedback was finally explicitly solicited in 2023. It was also aided by several naive ideas about human nature and incentive systems in general.

----

Again, the people you think of as "mods" are overwhelmingly not.

I have the view of a curator - an informal role that anyone can adopt by simply reading the meta site, understanding policy, and trying to help out with the process. Granted, it takes 3000 reputation to cast close votes, but anyone can submit edits, and it only takes 5 reputation to participate in meta (waived if it's about your own question being closed), 15 reputation to flag posts, and 50 to comment (and explain what's wrong with a question).

You say you have 100k reputation there. That's more than me. Yet I take all the actions you complain about, and have at times been very active doing so (for example, I added or moved hundreds of duplicate links to https://stackoverflow.com/questions/45621722 , and have gone weeks at a time running out of daily close votes). I'm not a mod.

There are 29 million user accounts, of which about 100k may cast close votes. There are 24 moderators.

Questions are in fact much too hard to close. Three separate people - who, by the above stats, are outnumbered almost 300:1 by those entitled to post answers - must agree. The purpose of closing a question is to prevent it from being answered until it meets standards; questions that could in principle meet standards are supposed to get fixed. But anyone can come along and just post whatever in the answer section; getting that deleted (answers can't be "closed" separately) is even harder; and the presence of that answer causes further problems.

The primary reason questions rarely get reopened is because closed questions overwhelmingly come from new users who don't care in the slightest about any of the process or goals, don't read the information that's given to them about what has happened, and thus never make any attempt to fix the question. (They may do this indefinitely, even after "deletion", by the way - and are expected to do so rather than reposting.)

What you think of as "normal users" aren't the ones who should get to decide what the site is or how it works. How people want an already existing site with 16 years of history to work is completely irrelevant. The fact that people have wanted it to work that way for 16 years is also irrelevant given that a) there are countless places already on the Internet that do work that way that they could use instead; b) they have been getting told off all that time, with varying degrees of tact and sophistication.

If people started trying to use actual Wikipedia as a Q&A forum, it would be correct for them to be shut down no matter how many people wanted to do that. I get that people's views on immigration vary a fair bit around here, but I imagine you'd agree that immigrants shouldn't get to write new laws for a country when they arrive.

Stack Overflow, and every Stack Exchange site, is not a forum, by design. The classic explanation of this (https://meta.stackexchange.com/questions/92107 ; especially see Robert Cartaino's answer) was originally drafted in 2011. Since it is not a forum, it is not a Q&A forum. It is a Q&A site, and people asking questions have always been expected to have a question that meets standards so that others can benefit from it. Of course, those standards have changed over time - as the community started to recognize patterns in questions that were causing a distraction and not helping to build up something useful. But it has always been with the fundamental motivation and understanding: look at what happens on traditional discussion forums; understand what's frustrating about trying to find or contribute information in that environment; be something else.