There are things that Slack cannot easily offer.
There are things that Slack cannot easily offer.
Email worked out pretty well, while IRC failed for reasons that are probably correctable.
But this software is not for expanding the audience, it's for limiting it, and their exposure. Much like Tailscale is not for extending your network with more nodes that can freely join, but for limiting it to a private subset you trust.
The Tailscale analogy isn't quite right because there are no real network effects involved. Most of Tailscale's utility exists even if no one else uses it.
Slack is only useful if your friends, coworkers, or partners use it. Same with Discord, and even open source alternatives for the most part.
Discord is winning because it's a dozen different communities in one single convenient client. Want your new chat platform to win? Convince all those communities to switch.
Just need a client app to make it look like something else.
Like slack did.