Hurd isn't exactly a useful project, but using Doom as the benchmark for the capability of an OS is a bit ridiculous.
Given that pregnancy tests can now run Doom, I have to agree with you. It was more of a symbolic thing than a technical difficulty at this point lol.
They can't, actually.
It runs on the screen of a pregnancy test, Doom is actually executed on an Arm Cortex M0+ based Adafruit Trinket.