In any browser app, having the "back" button do something sensible is Rule #1. It's the closest thing we've got to a universal UX paradigm. Many people are used to having a dedicated back button on their mouse, or a shortcut gesture, etc.. losing that interaction would be a continual irritation in any app you use often.
(and - because it seems to matter - Slack's web app works intuitively in this respect).
In any browser app, having the "back" button do something sensible is Rule #1. It's the closest thing we've got to a universal UX paradigm. Many people are used to having a dedicated back button on their mouse, or a shortcut gesture, etc.. losing that interaction would be a continual irritation in any app you use often.
(and - because it seems to matter - Slack's web app works intuitively in this respect).