They went from making ball point pens in the 1980s to flying a rover Mars in 2021. So what if HarmonyOS is just rebranded Android? They modified it for their own designs, put in a few backdoors and it will achieve its purpose, capitalizing on the work of Westeners. They are standing on the shoulders of giants.
HarmonyOS is absolutely not just rebranded Android. That is total nonsense, and that Ars article is ridiculously bereft of any understanding of HarmonyOS.
HarmonyOS supports multiple kernels including Android/Linux