If endocrinology was the most talked-about, hyped, and invested-in form of medicine I think it would be fair. DL is where an enormous amount of AI growth and progress is.
hyped things are made hype from a belief that it can be 'done' therefore invested in, but that can be done in one part of ML, which doesn't give any reason to say it generates all intelligence for a machine for human tasks.
ML is one family of approaches for knowledge acquisition in AI, but far from the only one (eg. logic based inference is another big one).
DL is a family of approaches in supervised ML. As the author points out, it's a subset of a subset.
But saying that this sub-subset "drives" AI is like saying endocrinology "drives" medicine: not the right mental model at all.