What I found was that there was a lot of repetition in the questions that were asked and so once the knowledge base was built up, less new stuff was being added.

There was a lot of blocking and downvoting of questions which was both a good and bad thing.

If you had an expertise on a certain topic, the questions were often very simple and repetitious (e.g. I knew a decent amount at relational databases), but also you'd get people asking for whole system designs which got a bit ridiculous.

It wasn't great for asking about little known products or libraries etc and I often found no one responded to questions on certain js libraries or BI tools. Which was quite annoying, maybe because it appealed more to certain types of developers.

I guess you served your time and most people don't want to be answering questions every day for ever! There was a guy called Tom Kyte from Oracle who ran a question site for over 20 years - it must have taken a lot of his time, but if you're out there Tom it was very much appreciated!