Isn't evolution a better analogy for deep learning anyway? All natural selection does is gradient descent (hill climbing technically), with no capacity for lookahead. And we've known this one for 150 years!
If you extrapolated those straight lines further, doesn't it mean that even small businesses will be able to afford training their own quadrillion-parameter-models just a few years after Google?
Is density even relevant when your computations can be run in parallel? I feel like price-performance will be the only relevant measure, even if that means slower clock cycles.