I'd like to take this moment to mention self-hosted, open source, and federated alternatives like XMPP and Matrix.
I'd like to, but unfortunately I don't feel like I can in good faith. Matrix is woefully immature, and suffers from a lot of issues, but I think is closer to being a functional Slack/Discord alternative. XMPP is much more mature, and works very well for chat, but doesn't have a nice package that does all the Slack stuff--at least not that I'm aware of. I'd love to be proven wrong there. I know it can be done, but if it can't be deployed quickly by an already overstressed team member, what chance does it have?
I'd like to, but unfortunately I don't feel like I can in good faith. Matrix is woefully immature, and suffers from a lot of issues, but I think is closer to being a functional Slack/Discord alternative. XMPP is much more mature, and works very well for chat, but doesn't have a nice package that does all the Slack stuff--at least not that I'm aware of. I'd love to be proven wrong there. I know it can be done, but if it can't be deployed quickly by an already overstressed team member, what chance does it have?