It does "work like that", this is literally my field. Evolution is a random walk where organisms higher up on a fitness landscape are more likely to survive. Ov

It does "work like that", this is literally my field. Evolution is a random walk where organisms higher up on a fitness landscape are more likely to survive. Over time, the probability of climbing the fitness landscape approaches 1. To claim that intelligent life would not evolve from simple life, you have to posit fitness barriers, i.e. steep discontinuities in the fitness landscape that prevent organisms from climbing. One of those barriers might be the jump from single-cell to multi-cellular in high heat/high entropy environments. But you haven't posited any such mechanisms. Intelligence has evolved multiple times on earth's history (just that the other species are extinct). So there is strong evidence that in earth-like environments there is no such barrier.