Think of it more like Lemmy, do you need to self-host a Lemmy instance to create a post? A community? No, and the same goes for Matrix.

The only reason to self-host Matrix is if you want to. You can create chat rooms on pretty much any server you like.

I personally use Matrix.org so I can just set up a chat room and itll be hosted there. Of course if you want to self host a matrix instance for you and your friends thats an option, or some of your friends can use the self hosted instance and some other instances (Matrix is a federated protocol).

I assume having your own chat room with your friends would mean self hosting?

Why would you assume this? There’s plenty of servers available and conversations can still be encrypted.

Voice chat is extremely lacking, though.

No