I agree, if I am working in a project, and my coworker is exchanging data about the project in a chat (Slack, or our embeded ERP chat, or whatever...), I ask him to put it in the BitBucket issue, or in our Task manager.
I hate having to search for something related to the task I am working in inside of a chat. Chats can be purged, they can be quickly a hell to look at, slow search and duplicated data makes it even more difficult to trim the good information, ...
Also better if somebody else is taking the lead on a specific task. Instead of dumping a chat history, he/she have everything in the appropriate task/issue.
I've also noticed forcing people (including me) to put questions/suggestions/remarks in the task/issue make people go straight to the point, and avoid unnecessary remarks since it will be peer reviewed by others.
I think that accountability thing is key. Tons of stuff gets lost in Slack threads and DMs that should be recorded somewhere in an easily searchable format.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.