Looking at streaming, is it not extremely great following that logic that we have dozen different services. All with their own "better" content. Instead of one lesser one with all content?
For example there’s many more bike manufacturers than car manufacturers. But if anything cars have improved substantially more in price:features over the years.
But Slack competed. It forced Microsoft to improve, then it lost. "Competition" doesn't mean artificially keep competitors alive when they can't survive on their own. If Slack was that much better then we wouldn't be having this convo because companies would see the value and pay for it.
The actual problem is that companies just aren't seeing that much value in Slack.