It seems like the question can be rephrased as, "At any point in history, have humans been able to advance technology in a substantial way simply because they wanted to, rather than by stumbling upon a way to do it?"
Most technology is incremental. Take flight, for example. The glider had already been around for a substantial amount of time before the Wright brothers solved the "control problem" and the engine problem. Those two problems were the only two left before powered flight was a reality, and the Wright brothers knew it.
For the singularity, on the other hand, there's no clear laundry list of problems to solve in order to achieve it. In fact, there's no clear way to even define AI, or at least define it in a way that can be meaningfully translated into current technology.
Maybe the advent of quantum computing will change this. I've suspected that AI is fundamentally impossible to implement on a Von Neumann architecture. But this is very easy to say from the point of view of a society which hasn't remotely discovered how to make AI work yet. It's similar in spirit to someone from the 1500s saying "I think electricity is fundamentally impossible to harness, because there's no proper medium to channel it" even though metal was quite widespread at the time. Humans just hadn't figured out how to fashion wires yet.
The only thing we can say for certain is that we don't know what we need to know in order to make the singularity a reality, let alone how long it will take.
