As part of changing laws in Europe, Meta now offers the option for you to chat with others using third-party messaging apps that have integrated with WhatsApp and that you choose to turn on.
Note: Chats with third-party apps are only available in select regions and may not be available to you.
I feel sorry for all in the wrong region.
This kind of interoperability is really useful for getting people to switch over. The only reason to use these apps is to talk to other people, so the network effect has a heavy hand on people’s decisions