I knew OpenWorm was struggling, but didn't know there were other unsuccessful projects. If no one can simulate C. elegans, despite all that's known about it, there's a fundamental lack of understanding so great that there's no surprise AI is stuck.
There was an attempt, funded at US$3bn, a decade ago, the Human Brain Project, to try to do something similar for the human brain.[1] That seems to have just turned into a funding vehicle for research in related areas.[2]