In many countries, EVERYONE has WhatsApp. In Israel it's how your boss, your work team, your kid's daycare, businesses and government offices communicate with you.
This happened well before Facebook bought them. The solution should have been to not allow the most popular instant messaging platform in the world be bought by a company whose revenue is based on spying on their customers. Unfortunately, the US has had functionally no antitrust action in the past several decades, and what little it has now only exists based on political affiliation.
Which is awesome from a purely technical perspective. The downside is it means your country's communications infrastructure is owned and controlled by Facebook.
If an open protocol version of WhatsApp existed and was universally supported by the default messaging apps on iOS and Android, I'd be all over that.