It was ... look up "AI winter". Vastly simplified, we collectively ignored ANNs until somebody figured out that we now have enough recourses to create larger ANNs than before.

Definitely familiar with the AI winter...which is why it seemed odd this current research as being presented as new. Guess it's just a rehash of the old ideas.

Which is a fine place to start, a lot of our current shiny toys are a rehash of old ideas in a modern context, https://people.idsia.ch/~juergen/deep-learning-history.html

You should post that here. (if it is not something that is already posted again and again).