[Question] Why don’t we think we’re in the simplest universe with intelligent life?

My gut instinct on metacosmology is that if were a simpler computation than our universe that produced intelligent life, we’d probably be there instead of here. I’m not sure that’s valid anthropics, but it still surprises me to see apparent assumption (in posts like this of the opposite conclusion—that there are many universes simpler than ours capable of producing intelligence. (EDIT: that post doesn’t actually make that assumption, and I don’t have another example ready. Still turned out to be a fruitful question, though)

(Yes, we know cellular automata can implement intelligence, but AFAIK we don’t know that they can do it more simply than by implementing a Turing machine stimulating our universe).

Is there an argument I’ve missed?