It’s encrypted anonymous communication capabilities.
Unless you enable it for every single chat (and IIRC only available for chats with only two persons, not group chats) there’s no encryption. Or did they change that? The only encryption that applies to most chats on that platform should be transport encryption via TLS.
In the end it’s about money. If one had to pay for environmentally damages (e.g. a new tax on $energyUnit, $resourceUnit,…) and you’d not only pay for the resources + some markup for the producing company and just external externalize the “worth” of the damages (read: the taxpayer,…), then it’s cheaper to use these services instead of humans.