It's a private silo with no public indexing by search. Makes it terrible for technical topics fine for a chat platform.
It's a bad hybrid of chat and forum. None of the advantages of rich forum posts and typically too may participants for it to be easy to follow. Noticeable if you are not in the main timezone as the others.
Discord has threads and topics, but these features are a bolted on afterthought instead of core functionality so it just doesn't work as well