Unpopular opinion:
It is perfectly fine to use a less secure/not ideal chat app.
You can use Matrix, Telegram, Discord, XMPP...
But you shouldn't tell the world that it's the best solution ever. And you should be aware of the flaws of each solution.
If you need some specific use-case one chat service provides and the others don't, it's fine to use it!
For instance, I like using XMPP because it's a self-hosted solution, and it has a simple interface. It isn't an ideal solution, especially regarding encryption and stability, but it's okay for the use-case I have (chatting with other friends).