We have Discourse chat which is now included in core by default.
You could always change the ‘New Topic’ to '‘New Post’ in customise text or this TC Customize new topic button text based on category or tag?
Discourse and Discord are both very good separately but work well together. See more in the blog below. They can both coexist but one is asynchronous and one is synchronous (discord) its a different way of communicating.