Using a full-blown GPU just for neural network inference is crazy inefficient. They should hire some blockchain dudes to build them custom hardware for one tenth of the price.
Google hired a bunch of chip designers to make TPUs for their ML people, so are highly optimized for this kind of work, which are currently on their 5th gen, and are available on their cloud.
(Disclaimer: I used to work there but not on them.)
(Disclaimer: I work for AWS, but opinions are my own.)