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.