On the one hand, talk of probability here seems meaningless and inscrutable.
Does it? I don't think so. There's a reason hydrogen is the most abundant chemical substance in the universe.
Most people, I think, are aware that in any sequence of coin flips, any individual coin flip is 50/50, and a consequence of this is that all permutations of any sequence of coin flips is just as likely as any other sequence. So apply this same logic to an old school TV which is showing static. Every pixel is randomised. So, that situation, why should it be that complex images are less likely than images without any complex structure?
The answer is simple - in the space of all possible images that screen could make - remember, every permutation of pixels is equally likely - MOST permutations don't have structural complexity, most of them look... random. Most pictures produced by a TV with randomised pictures look random, because most possible images don't have any sort of ordered complex structures in them.
The same is apparently true in the physical universe.
Randomised processes naturally (and tautologically?) choose more likely classes of configurations more often than they choose less likely classes of configurations, and the class of "complex structural arrangements" is almost always much smaller than the class of "apparently random arrangements".