It's a retread of another (also baffling) "Why OpenAI Should Build Slack" post from a popular AI Substack.
Just more empty grist for the AI adjacent content mill. "Slack sucks" doesn't let you draft off the current hype zeitgest, so we get "content" like this.
A large portion of the AI related response pieces fail to reference what they're responding to. I have to assume it's a side effect of how they're using AI to write them.