What would make me and my users move to an alternative comes down to the integrations and the seamless mobile transition.
The chat part, channels, tagging and upload of asset isn't enough, there are already alternatives to slack offering this that are open source.
I love what you're offering, I hope you get there.
Thanks! You're 100% right—the ecosystem is the hardest part to replicate. We know we can't match 2,000+ integrations on day one. Our strategy is to nail the core "chat + search" experience first,and then offer a dead-simple, developer-friendly API (think "webhooks on steroids") so teams can easily pipe in the 3-4 critical tools they actually depend on (GitHub, Jira, Alerts), rather than waiting for us to build a massive library.