And, recursively, Slack is pretty terrible.
It’s amazing to me that a “work communication” tool has no inbox.
Whereas with my email inbox (which works the same on desktop or phone), I can read the messages without losing them. I can read all the new messages, work on the ones that are most important and earliest, and only when I’ve dealt with them do I archive them and remove them from the list. That way I can always look at my inbox to see what needs to be done (not what I’ve yet to read).