Dont forget Allo. Goes to show how much role luck plays in these companies' success and it is so strange that others still copy what Google, Amazon and these companies are doing thinking that they have some sort of management hack or routine which makes them successful but in fact they become successful despite of their bad practices not because of it.
Still wondering how Zoom managed to pull that off - granted, they have a single offering, but describing it as "stable" is a stretch. And the UI is such a mess, don't get me started...
The chat mess with Google Talk, Hangouts, Meet, Duo, etc. was quite sad to watch because Talk was a great product.