To break the attack in this paper, you don't even need a hardware RNG; you just need hardware AES, like most modern platforms have (and like most mainstream operating systems use by default).

With hardware you have to always worry about some "physical" error, and if the hardware doesn't have sufficient diagnostics, you will never find out in software, because after whitening even a constant zero series from hardware looks indistinguishable from the failure-free output.

Intel itself ships expensive accelerator cards that have "zero software" in key seed generation capable of generating multiple gigabytes per second of random bits.