Okay I made this comment based on the title, assuming it meant a sort of "reimplementation" of the linux kernel running in userspace, similar to gvisor (an application kernel).
But that does not in fact seem to be what this is. In fact I can discern no architectural decisions that would differentiate this from Linux in any way. So what is it? We vibecoded an OPEN SOURCE piece of software??? Genuinely so confused by this...
I agree that it is mostly entirely pointless; but I don't think the goal was to make something useful, rather to prove that "HDAE" can in-fact produce a kernel capable of running some unmodified Linux applications