* your hdd failed? Use a raid
* your power went out? Use a UPS
* your DNS went down? Use a fallback (slack2)
* your whole datacenter flooded? Good thing you have multiple replicated cloud instances that seamlessly take over
See, these are the issues that "the cloud" was supposed to solve. Not give us the same problems as before, just with a recurring bill for "chat as a service".
And inb4 "chill Mike it's just a chat server not life support firmware" yeah but slack is the most trivial software you can think of: send text from one computer to another. I see no reason this service can't be nearly as reliable as life support firmware in 2018. We've had over 30 years to get this right. Raise the fricking bar.