It's the ecosystem. Without an ecosystem there will be less adoption and consequently less investment in the OS. Where I stay, so many services offered exclusively through Android/iOS apps with no alternative. Even government services are slowly excluding the web and becoming app only. There is an implicit expectation from everyone that one will have either an Android/iOS device and this only becomes stronger with time.

I don't know how many people realize but what can result from this can be very dystopian and is scary. But the best possible outcome from this I hope is that some day a wise government realizes how much of daily life is dependent on two corporations and passes regulations to standardize app runtimes. You should be able to publish applications that can run on any OS. Only then we'll see competition in the OS market.