pretty similar to whatsapp. they boast end to end encryption, but business account (all of them now) uses the facebook server's key, so that the business can give access to several other clients to answer customers. they still call it end to end encryption, and this was actually the last crap the original founder accepted before leaving with lots of money on the table.
I use WhatsApp dozens of times a day, and interact with business accounts every couple months at most.
In most of the global south, 100% of business have a whatsapp. In those places it pretty much replaced telephone and the green whatsapp icon is now what the current young generation recognize as the we did the black telephone outline on a business front next to a number.
and if you own a business, or is self employed, it is even worse: you live by that app.
As an expat, this feature has enabled me to transact with locals from the convenience of my phone, even though i don't have any local line and i will not bother to get a local SIM card, nor do i want to have a US SIM and a local one interchangeably.
It also enables me to be very effective when requesting services on demand, and cutting thru the on-hold time, disconnected calls, or the needless chitchat.
I have many bad things to say about WA, but making living more difficult in a foreign country is not one of them.
Telephony is an artificial monopoly. There's not a single reason why you cannot call everyone around the globe for mostly free, as whatsapp proves. Yet here we are.