Not at all, I think closed private systems are far better (better products, support, service) but when an entire company runs its operations on a single system

Not at all, I think closed private systems are far better (better products, support, service) but when an entire company runs its operations on a single system like Slack, there is a big risk when it goes away and you need contingency. I’d still rather be on Slack and suffer a day of lost productivity than force people to use only email or IRC.