I'm in the lead-weight-dragging tail (working in a bank using Teams, but dealt with this at the last job in Slack as well). The major hassle seems to be getting people to understand this is asynchronous communication (perpetrators are both developers and executives) and this problem seems to stand before the rest of the more sophisticated complaints evinced here can be even addressed.
A: Hello B.
[... typing/waiting animation]
B: Hi.
A: Good afternoon.
B: All clear for transmission, A. What's going on?
[... now B is derailed, waiting several minutes for A to compose his thoughts and type and edit them]
For all the pseudo UX voodoo we go through, can we not do something to give a hint that this is not a fucking phone conversation or something that requires a Q code? Or am I exiled to some benighted colony? Why is this not the first-order problem to be dealt with?