The quality of questions is abysmal and getting worse at an exponential rate. It used to be a site where experienced developers ask focused, well-written questions, after doing some work to solve the problems on their own. Sure, there have always been crappy questions, but as recently as three years ago, the bulk of the questions on the front page were decent.
A huge portion of questions now are homework assignments where the student just wants a canned answer and hasn't made an attempt to solve the problem; are written by people with such a poor grasp of English that they're worthless; endless repeats because no one has searched for existing answers; etc.
I also used to moderate on a daily basis. The flood of low-quality content wore me out, but what really ended my moderation was constantly being challenged by the fake entries they shove at you to "make sure you're paying attention" while moderating. The bot suspended me from moderating a few times because, when presented with posts that required moderator attention, I didn't pick the exact category it thought needed fixing. I'm doing free labor for you and you're going to be a dick about it? No thanks. It's no wonder the quality has gone to shit.
At one point I was "top 1%" in a number of topics, moderated, voted in elections, etc. Now I barely use the site. As much as I dislike Reddit, I increasingly click on Reddit links when I'm looking for answers.
Stack Overflow is still a valuable resource but it's all downhill from here.