It's always a fact of life that there are more questions than answers. This is true of all SE sites, and all questions that have ever been asked in general, even questions unrelated to technology long before the Internet was invented.
That's because answers require a significant amount of work for humans (usually) to produce something useful and expedient to solve a problem; but in almost all cases where any "solution" is provided (as a result of someone doing work), the solution is imperfect, leading to yet more questions.
Just think about it: nearly all questions on Super User are about some piece of hardware or software that is supposed to present a solution to a problem. That is, for each "answer" we've already come up with, there are dozens (or hundreds) of questions! And the more complicated and comprehensive the answer (say, an operating system), the more questions there are!
Humans are never satisfied with what they've got, which means they can always conceive of how it'd be better. But in about 110,000 cases, at least, the following series of actions has not taken place, in the right order, to provide an answer:
- Someone asked a good question, or a bad question that nobody who cares about curating the site has bothered to flag or vote to close/delete.
- Someone who's had experience in that area has seen the question.
- That someone was either extraordinarily lucky in their ability to have already gone through the same problem, and can thus very quickly produce a solution; or
- That someone was lucky enough to type the right search terms into a search engine to find someone else on the Internet who has posted the solution to the same problem or a similar enough one that the answerer can put two and two together and write down what he/she thinks is a likely answer.
- The solution is simple enough that the answerer actually has time to do this, considering they probably work for a living (or do something else besides answer questions on Super User during their free time) and spend between 1/5 and 1/3 of their life sleeping.
- The answer wasn't spam that gets voted into oblivion or flagged and nuked.
In short, every time a question gets answered with valuable information, it's a freaking miracle. The scope of questions that can be asked is so broad that there's no way we'll ever have time to answer them all.
And because software becomes obsolete so fast, and peoples' use of software and hardware becomes obsolete so fast, many times the person who asked the question, as well as the rest of the community, will have moved on from the topic of the question, to the point where almost nobody still uses/cares about it. The question then becomes something of a permanent tumbleweed.
The system already has an automatic algorithm in place to delete many such questions, unless they receive enough upvotes that it decides to keep its automated hands off of it.
But for the rest, it's just a fact that we'll permanently accrete more and more unanswered questions. Welcome to humanity.
And no, this isn't a storage problem for Stack Exchange. Last I recall, the entire Q&A database for all of Stack Exchange compresses down to a handful of gigabytes -- it's some number much less than 50 GB. By the time this number becomes 1 TB, we'll have commodity 10 TB SSDs.
The funny part about human text is that it's extremely compressible, meaning that it's very inefficient and doesn't really say a whole lot that hasn't already been said. And compression algorithms are so good that for human text related to a particular domain (in this case, technology), the size of the compressed data might increase slower than linear (linear would be, doubling the input size also doubles the output's size, but I think the compression can do even better than that).