[borski]

Losing track of information, and things not getting written down or forgotten about.

[icapybara]

It gives a lot of power to The One App To Rule Them All though. And what happens when the company decides to switch to another system in 5-10 years?

Email at least has stood the test of time- Slack has not.

[ghaff]

I still tend to favor email for a lot of things but understand that's increasingly a minority opinion especially for things that aren't routine updates, promotions, announcements, etc.