Umm, customary, tongue-in-cheek reference to McCarthy's proposal for a 10 person research team to solve AI in 2 months (over the Summers)[1]. This was ~70 years ago :)
Not saying we're in necessarily the same situation. But it remains difficult to evaluate effort required for actual progress.
[1]: https://www-formal.stanford.edu/jmc/history/dartmouth/dartmo...
A thousand years ago we hadn't invented electricity, democracy, or science. I really don't think we're a thousand years away from AI. If intelligence is really that hard to build, I'd take it as proof that someone else must have created us humans.