If you wanted to launch a new mobile OS in 2018, your best hope would be to have very good support for Android apps and the Play Store. You'd still fail to attract users and developers to your platform, because why use an Android compatible device when you can get the real thing, and why target such a device when it can run Android apps anyway? You might as well just design an Android device at that point.
@xj That's pretty much what was implied in what I wrote above, though.
NewOS + New Device have to offer something that Android/iOS can't. some next level shit that cuts hard against the grain for both Google and Apple. they have tons of resources, so it has to be something that they can't even fathom as an organization. else, they will copy and smother you.