Like Facebook groups. Those public group channels can be awesome, especially in early stage but as they grow in popularity, they tend to become more noise than value. Just look at the SMT Telegram group and you can but facepalm (mostly).

That’s where Slack excels, easy new channel creation. But for slack to be valuable for projects (archives), Slack is expensive. Very expensive.

There is an other awesome open source client, riot.im but it isn’t blockchain based. Nor widely popular actually.