Two fundamentally different venues, and conflating them leads to poor results: the work in each is not the same.
Channels with discussions
The author publishes, readers comment under the post. The audience is large but passive: they came to read, not to talk. Comments are seen by whoever opens the discussion — usually a modest share of readers.
The upside is being first under a fresh post, where everyone who looks in sees you. An early comment here is worth several times a late one.
Topical chats
Everyone talks to everyone. Smaller audience, higher engagement: people came specifically to converse. Your reply is read in the flow and lands as a participant's remark rather than a comment under someone's post.
The downside is stricter moderation and higher visibility of newcomers. A first message from an unknown account is often auto-deleted.
Which to pick
For recognition and volume, channels: there are more of them and discussions are calmer. For quality contacts, chats: fewer people, each closer to a conversation.
Why you need both
Channels give breadth, chats give depth. Channels alone produce views without dialogues; chats alone the reverse. Collecting both lists is on the parser page.