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.
There is still lots of work needed on this regulation. You still need to install WhatsApp to be able to use other apps, and then encryption (however safe it is in the first place is not a topic of this post) is weakened or completely broken. Second as of now only very few fringe messaging apps support it.