>>13187505>>131875562 spatial dimensions might work for very simple life, but not intelligent life. if intelligent life requires interconnected information processing units, you cannot have high level of interconnectedness in 2D.
the highest density of connection you can achieve is only average 6 per neuron, whereas it it is inifinity in 3D. think of the 3 house+3 utility problem. you just cant connect enough things together in 2D