Earlier quoted context omitted.
What's the alternative? Be only on one platform? Not viable today. Implement 5 different apps, usually not viable. The platforms are fragmented and the user pays the costs of that in the end, one way or another. If you hide it by increasing development costs, the price of the app ( or amount of ads or premium only features) must go up to compensate and the user pays the cost as well. Edit: downvote all you like, ther…
Microsoft easily has the resources to write 5 chat app UIs.
That's typically the smart choice.