Zulip (and Zephyr) is indeed much better for threads. You can actually find them to use them later. In Slack, it's more like a side-bar, instead of a topic that

Zulip (and Zephyr) is indeed much better for threads. You can actually find them to use them later. In Slack, it's more like a side-bar, instead of a topic that you could come back to later and anyone throw into. Whereas I used threads all the time in Zulip, they are really not great in Slack, and mostly just useful for reducing noise for off-topic discussion.