It's really an engine for revealing people's true preferences for messaging, which, for many people, tend to be that they want all the ergonomics of Slack a lot more than they want cryptographically sound secure messaging.
What's hopeful in all this is that Signal is, slowly, catching up. Slack can roll out new features just by assigning a couple developers to it, and Signal has to coordinate new cryptographic research --- not just new cryptographic research, but research that produces something deployable at scale within the resources of a project like Signal! --- so Slack (and Wire and Keybase) are at a permanent advantage here.
But over time, Signal gets more and more usable without having to consider tradeoffs.
What's hopeful in all this is that Signal is, slowly, catching up. Slack can roll out new features just by assigning a couple developers to it, and Signal has to coordinate new cryptographic research --- not just new cryptographic research, but research that produces something deployable at scale within the resources of a project like Signal! --- so Slack (and Wire and Keybase) are at a permanent advantage here.
But over time, Signal gets more and more usable without having to consider tradeoffs.