Actually once you start travelling outside the USA you realize that everyone uses whatsapp for texting friends and businesses. No one uses SMS. At least with whatsapp you get the profile picture and a bio - which is a little more trustworthy.
Such a protocol should allow people to report whether this number is trustworthy or a scam.
Because everything else is worse.
> Actually once you start travelling outside the USA you realize that everyone uses whatsapp for texting friends and businesses.
Case in point. Maybe giving a communications monopoly to a single private company that's completely unaccountable isn't a great idea? This is how we get https://xkcd.com/743/
I wanted to highlight that the user experience is better than SMS. For example when I add a phone number I have a higher level of trust that it's a verified business. Having read status feature is also good. Last online tells me if this is an active business number.