Just out of curiosity, do those 7.5+ million accepted answers include those closed as duplicates? Because by far my biggest complaint is finding the exact question I have was closed as a duplicate and links to a question that is useless at answering my question.
In that case you can vote to re-open and perhaps even post a bounty. Although bounties tend to invite lots of low-quality, low-effort answers just on the off chance that they might be the top-voted one once the bounty runs out.
I feel you. I've taught myself programming between 13 and, well, I'm now 23; so by the time stackoverflow came around I had figured out how to solve things myself. When I have a question, it's usually either opinion-based (bad fit for SO) or not a common question.
I'd say 1:20 is a good estimate if I ignore answers that didn't read my question (which is most of them), but indeed the facts disagree.
Back then I didn't speak proper English, and how many questions were actually covered on SO in the beginning? It took some years to get to where we are, both for SO and for my English ;)