I think your concern is unnecessary. From a technical perspective, the Hongmeng OS certainly can be a equally good smartphone OS IF Huawei decides to do so.Could you tell me if Huawei Hongmeng will be for smartphones or not? I've read recent report it says not(citing some Huawei director) is it true?
Android is a Linux/Unix variant with a Java VM sitting on top of the kernel, then Android apps sitting inside the VM. It is no different from a Linux desktop, which is not far from a Mac or Windows.
Huawei's word, if you pay attention, is that Hongmeng was initially intended for IoT before all the Trump farce, but that intention has no limitation to only IoT. The real concern is the app base (how many Android apps can be run smoothly). Windows Mobile and Symbian died NOT because of technical shortcomings, BUT rather lack of apps (adaptation of developers).