This really depends on the topic. I mostly stick around the functional programming tags (Haskell and OCaml) and have seen all sorts of difficult questions answe

This really depends on the topic. I mostly stick around the functional programming tags (Haskell and OCaml) and have seen all sorts of difficult questions answered, often very well. Sometimes SO is basically the only place to find an answer at all. Especially in the Haskell tag, even extremely involved and non-trivial questions rarely go unanswered.