This is kind of interesting. Slack is actually an acronym for “Searchable Log of All Communication and Knowledge”, and that is how they use it. It’s not a messaging platform, it’s a repository of info. They post to topics for the purpose of logging information on that topic that others can later see, not to people for the purpose of communication.

Apologies for the Threads link- this worked just in a browser for me even without being on Threads