Who says we need a quantum leap? Most technologies progress by slow iterative improvement. The idea of sudden significant breakthroughs is mostly a myth. Even in biology, the human brain only has some slight differences from other primates. Which in turn aren't terribly different from other animals.

In any case, I think there has been tons of progress since the 80s. Taking the best algorithms from the 80s and running them on modern hardware would fail. The core idea of backpropagation and gradient descent was there, but not much else.