Everyone here throwing shade at Stack Overflow is clearly too young to remember the horror of Experts Exchange and every other technical help site prior to SO. For nearly a decade, it was absolutely transformative as a technical help resource. It certainly had its faults, but it was so far ahead of the other options as to be game-changing.

I believe that the main reason for SO's decline starting around 2018 was that most of the core technical questions had been answered. There was an enormous existing corpus of accepted answers around fundamental topics, and technology just doesn't change fast enough to sustain the site. Then the LLMs digested the site's (beautifully machine-readable) corpus along with the rest of the internet and now the AIs can give users that info directly, resulting in a downward spiral of traffic to SO, fewer new questions, etc.

Vale, Stack Overflow. You helped me solve many tricky problems.