It requires significant effort for us to build out support and triage issues on each browser, so we're focused on providing a great experience in Chrome and our desktop apps. We are listening to all feedback, though. 👂
I’ve seen this get raked a few times. Slack is a product, and they have decided to provide the best experience in their apps, then Chrome browser, then everything else. I use the macOS app, can’t see advantage of using browser. None.