This is changing though. A fair number of solutions such as Slack are easy enough to use and get a hold of that teams within large enterprises can simply start using them.
Microsoft has it’s own internal chat tool (which is terrible), but this strategy keeps their clients locked in while the buyers stay happy
It's 2019, our software should have gotten to a point where the computer is working for us, not the other way around for God sake. Nobody should still be working a job where their entire purpose is to make the computer do what you need it to. No wonder so many people feel like they've lost their sense of purpose.
Of course, Slack already isn't that simple. The authentication model seems insane, and no one can ever explain it to me when I ask.
It's nice that me@gmail.com and me@corporate.com can be logged into different slacks in the same electron app, but why do I have different accounts/passwords for me@gmail.com for different slacks? It's all the pain of federation without any clear benefits.