From reading the top comments, an interesting conclusion is that messaging apps like Slack do not have drawbacks due to technical problems, but due to cultural

From reading the top comments, an interesting conclusion is that messaging apps like Slack do not have drawbacks due to technical problems, but due to cultural problems. These problems can be mitigated in a work environment where you can enforce cultural mores, but in a social environment (like within a group of friends or some other non-work related community) this becomes more challenging. There is probably room in the market for a messaging app that prioritizes reaction communication and suggests that more thoughtful communication take place in a more permanent project management tool.