I don't really get why there is so many Slack alternatives coming up these days. On every post like this there is tons of comment linking to other Slack alternatives, it's not like this is gonna be _the_ Slack-alternative. Here is a non exhaustive list : RocketChat : https://news.ycombinator.com/item?id=9624737 Let's Chat : https://news.ycombinator.com/item?id=9040841 Friends : https://news.ycombinator.com/item?id=94…
So different use cases mean a different product might be better. Particularly if business concerns limit how one can use existing products.