His predictions were based in part on an analysis of the human brain.
Kurzweil writes that by 2010 a supercomputer will have the computational capacity to emulate human intelligence and "by around 2020" this same capacity will be available "for one thousand dollars".Computers will have human-like intelligence and pass the Turing test by 2029, and the Technological singularity in 2045.
We are on track, more or less.
A lot of people assume that ChatGPT, Stable Diffusion, and related AI technologies were made possible by technological breakthroughs in software neural nets by Google, OpenAI, academic researchers, and others.
This is partially true, but the neural nets of today are not much different from those of the 1980s. The big advances have been in computational capacity. Moore's Law is dead, but the amount of computation of cheap gaming cards has dramatically improved.
We are seeing huge AI advances now, just because computers have caught up with the human brain. That's all.