I think you’ve got it backwards; if you picked at random a universe among all mathematically possible ones with probabilities proportional to (number of sentient beings in it)*2^-(Kolmogorov complexity) (i.e. SIA+Solomonoff induction), you’d most likely get a universe barely as complex as needed for sentience. If on the other hand the laws of physics turned out to be much more complex than that...
I think you’ve got it backwards; if you picked at random a universe among all mathematically possible ones with probabilities proportional to (number of sentient beings in it)*2^-(Kolmogorov complexity) (i.e. SIA+Solomonoff induction), you’d most likely get a universe barely as complex as needed for sentience. If on the other hand the laws of physics turned out to be much more complex than that...
(Or at least that’s what I thought right after reading Good and Real. But it looks like the sum (number of sentient beings in it)*2^-(Kolmogorov complexity) might not even converge.)