These brains are a lot smaller than a human brain---only about 2-5 mm across. While it's almost certainly a mistake to conflate size with complexity naively (s

These brains are a lot smaller than a human brain---only about 2-5 mm across. While it's almost certainly a mistake to conflate size with complexity naively (songbirds are capable of pretty complex behaviors), I think it's much safer to assume that if human brains were capable of being much smaller while still allowing complex behaviors, they would be. Otherwise, we would probably gestate longer---compared to lots of other primates, humans are born "premature" in terms of developmental completeness. Also, as other comments have pointed out, these organoids don't really have any neural inputs, so it's unlikely that they're wired in a way that is at all analogous to real human brains.