What can computers do today that they couldn't do 40 years ago? They are essentially the same, processing the same types of data, running on the same types of code, just with vastly more computations per second possible.

We've made no advancements in terms of any basic intelligence or capability. A completely different computer architecture would be required, and it remains to be seen that such a thing could even be created. I don't know of any chemical processes or systems that can be developed to the degree of precision and complexity of life, or even if would ever be possible without using organic (carbon based) molecules and a system similar to life.

There will be no Singularity in our lifetime.