I've actually been using HarmonyOS for half a year now, and it feels pretty good — the notifications and system smoothness are on par with iOS. The reason I don't use an iPhone is that I need NFC access control, which iOS doesn't support.
Huawei has invested a large amount of manpower to station people in major companies to help develop HarmonyOS. I think they have already broken the vicious cycle of "no users -> no apps -> even fewer users."
Moreover, in the current AI era, it has become easier for Chinese developers to port software to HarmonyOS. For example, Moonlight, the streaming software I often use, has several natively customized and optimized versions available in the HarmonyOS app store.