Whatsapp is dominant in most countries in world, it's not overstating. Your 3 country example mean nothing in comparison.

If by most you mean 50% then sure. But the other 50% countries prefer to use different app. Be it Facebook Messenger or Telegram... In my eu country nobody has WhatsApp and its not uncommon. Network effects are at play so it's what became popular first.

The real point of the original comment was that outside the US iMessage is not dominant and so nobody cares about what color a chat bubble is.

I appreciate that I was a bit too confrontational in my first reply and should have just added that WeChat, Line and Telegram are also used (plus many others), not just WhatsApp.

Why I think I (over) reacted is that it was, to me, an example of only partial escape from US American insularity. They understood that ppl outside the USA don't use SMS much, but only suggested a US American messaging platform as what was used instead.

Did we read the same thing? There is nothing about color of chat bubble but there is "they all use WhatsApp". No they don't. Not all. More like half.