The prediction that a new technology that is being heavily researched plateaus after just 5 years of development is certainly a daring one. I can’t think of an example from history where that happened.
Perhaps the fact that you think this field is only 5 years old means you're probably not enough of an authority to comment confidently on it?
Neural network research and development existed since the 1980s at least, so at least 40 years. One of the bottlenecks before was not enough compute.