Way more complex to be sure. The "more powerful" part requires a bit of interpretation. One transistor certainly can't do the work of one neuron, even given

Way more complex to be sure. The "more powerful" part requires a bit of interpretation. One transistor certainly can't do the work of one neuron, even given forever to do it. But a not-too-large-to-count collection of transistors can do the work of a single neuron, and do it much faster. I don't know that 100 billion transistors can out compute 80 billion neurons with a 100 trillion synapses, but it's not implausible to me. Neurons have a firing rate on the order of 10Hz; an entire CPU can be clocked at 100 million times that rate. It's certainly not obvious that those 11 orders of magnitude can't make up for the functional limitations of transistors. Obviously standard microprocessor architectures are not comparable to the architecture of the brain, so a true head to head comparison is impossible, but it's not absurd to imagine we've achieved or surpassed parity.