They didn't? I'm not sure what you're saying here. Are you arguing intelligent design or something? Because the standard evolutionary theories postulate that humans did, in fact, spontaneously arise from a heat bath (the heat coming from the Sun).
That's not what I typically think of when I hear the word "spontaneous". Spontaneous emergence sounds to me like lightning hitting a swamp over a period of time, and then by a pure chance arrangement of molecules, a fully formed swamp man comes out of it.
That's way different than an evolutionary process.
> Do you think creating a 3D universe (like that being worked on by open.ai), putting the evolvable agents in it and trying to make them evolve learning and intelligence is a good idea
Basically simulating a universe, seeded with some things we think are already somewhere along the road to intelligence, then seeing if progress is made just by simulating for a long time.