I wonder if you look at the stats whether or not SMS is actually the most popular form of communication on Android. I live in the US, where I use iMessage and SMS is the most popular, but I hear all the time on Reddit that no one uses SMS outside stupid America and everyone uses WhatsApp/Signal/(Chinese one I'm forgetting).
Google needs to pick one, no doubt, but I wonder how relevant it is that they do (Android has much of its market share outside the US).
This is a fair point, and I wouldn't be surprised if what you are saying is correct.
That said, saying "Google's startups-within-a-big-company strategy has driven most users outside of Google's chat ecosystem entirely" isn't a whole lot better.
It depends on the country. Some places you have to pay per SMS, some places it's free. SMS cannot be sent across borders, a big problem when traveling or living abroad.
WhatsApp is free SMS, from and to anywhere. It's an attractive offer for most of the world.
Google needs to pick one, no doubt, but I wonder how relevant it is that they do (Android has much of its market share outside the US).