Yeah this is it. It's very unlikely to see something which cannot be decomposed into similar parts come into existence. Something highly complex and irreducibl

Yeah this is it. It's very unlikely to see something which cannot be decomposed into similar parts come into existence. Something highly complex and irreducible. But simple things are likely to come into existence. So given that we see complicated things, we should assume that they are reducible, and that they came from simpler things. This creates the appearance of a "trend" as you say. But it's really that the complicated things couldn't exist before and now they can. Another effect is that it's possible to be more fit (in the Darwinian sense) when you are more complicated. The fittest system with complexity n is <= the fitness of a system with complexity >n. The rate at which things are destroyed is inversely proportional to their fitness (definitionally). So more complicated things can be better at staying around. See also: https://en.wikipedia.org/wiki/Assembly_theory https://en.wikipedia.org/wiki/Assembly_theory