The DoE has also been a fairly active purchaser of GPUs for almost two decades now thanks to the Exascale Computing Project [0] and other predecessor projects.
The DoE helped subsidize development of Kepler, Maxwell, Pascal, etc along with the underlying stack like NVLink, NGC, CUDA, etc either via purchases or allowing grants to be commercialized by Nvidia. They also played matchmaker by helping connect private sector research partners with Nvidia.
The DoE also did the same thing for AMD and Intel.
[0] - https://www.exascaleproject.org/