We already had not one, but multiple. They lost to android. I imagine there were multiple reasons, really, but one of them seems pretty basic: simple SDKs. Even when there was no Android apps, making one was easier, than making... whatever. Now, when there are thousands (maybe millions? I have no idea) Android apps, I don't really see anything else catching on. To be fair, now there is this react-native approach, but still, all these permission frameworks, drivers, really necessary apps nobody will port and everybody needs...