Stack Overflow might be the greatest receptacles of human knowledge on programming.
But I would argue that it usefulness only extends to its body of knowledge. As a service and/or community it has been pretty terrible for a long time:
If you were a new user trying to learn programming, it was maybe one of the most toxic resources available. I don't think I have posted a question since 2019. And even there, the only thing the average user could expect was a snippy response from someone who barely stopped to read your post. And/or a mod deletion because a similar-ish question already existed (regardless of whether it had a satisfying answer).
At a certain point, all the meaningful questions have already been asked. The site exists to collect novel new problems and not help people with iterations on existing problems.
(Also, underrated is the extent that the industry has homogenized around a couple of frameworks that are used for everything. I think it's telling that the peak of StackOverflow coincided with the era that React was taking off, to just name one).
StackExchange is pretty friendly to beginners in my experience. I used to post straight-forward questions on math and stats on math SE and stats SE. I got answers within hours and sometimes minutes, and the answers were spot on.
Like the Internet, it got less friendly the more popular it got. And there were no measures in place to retain and reward the friendliness.
Jeff Atwood thought a lot about this when he subsequently created Discourse. Nudge people to treat their community members nice.
Early years SO was optimized for people helping people. Later on they ruined the site by optimizing for tidiness ... and griefing users (especially new ones) off the site in the process.