You should stop by #feedback in chat.zulip.org and share your ideas!

Regarding the history: Slack had very effective marketing, powered by a lot of venture capital. And HipChat was a weak product that had an embarrassing total hack, which did not leave customers with confidence that their data was safe there.

Zulip is not venture-funded, so we're reliant on people sharing it with others to get the word out.

As a side note, I don't think Slack could have succeeded if it launched today. Microsoft Teams has far far more users as Slack, and it's slopware. You can thank the end of anti-trust enforcement for that.