Different platforms have become the standard de facto in different regions of the world (iMessage in us, WhatsApp in Europe, WeChat in china, ..).
All of these platforms belong to private companies.
A sane landscape would be having platform interoperability, at least for the most common features and then let companies compete on features, not on user networks.
In Europe it is virtually impossible no to use WhatsApp, especially if you have kids. I don’t like it, but it’s one of the service I use the most, because I’m forced to.
What's the problem exactly?
To have a standard? Isn't that what phone numbers and SMS are if you want a standard way of reaching someone?
If you have other standards, you reduce innovation because in order to change anything, you have to get 100s of companies to agree and comply.
But if Whatsapp, iOS, Viber, WeChat, etc wants to make something better, they can write the code and release it tomorrow.
Users have chosen the private model. It's better. It's faster. It innovates more. If you want a standard, it'll just become like SMS years later. I don't want one single app. Each app does something better.
This is why we have regulated interoperability on many mass-market technologies. Imagine requiring a Ford to use certain gas stations or a Sony TV to view certain channels. There is no upside for the consumer when mass-market products leverage their popularity to create walled gardens.
If you want a group chat with friends, there are a bunch of apps for that. If your friends wants those cool features but refuse to use any one of existing apps besides iMessage to talk to you, then they are not your friends.