It runs on the same hardware you and me could buy if we weren’t poor. And no, people don’t write their own kernels or drivers because your vendors will tell you that you can use their supported version or get fucked when something breaks. Yes there’s some optimizations for like enterprise hardware but everyone will half a brain cell can and should tweak the system at that price point. Idk you don’t sound like someone who knows a thing about HPC. Sorry.