Should aim to do responsive design. This is more feasible with Sketch and other tools now.

http://bradfrost.com/demo/ish/

If this is trying to solve the bad public transportation in SF, money and resource well wasted. We don't fix bad water in the fishing tank by putting in more expansive fish with the hope they'll purify the water.

If you use Photoshop, there's also Specctr https://www.specctr.com/

For such a high-profile designer to make such a statement, very unproductive. Sure the app is not perfect in a "native" way, but how many companies out there who have a perfect "native" mac app AND also worth billions…

The trade-off was speed of execution to bring important and consistent experience to multiple platforms at the same time, and that exact decision (imo) has contributed directly to their success in a short amount of time.

So get your "iMessage for design team collaboration" and "web-view" babel out of here. For all we know, not many Slack users are using the desktop mac app.

ps: if you're using Slack to "organize" files, you're using it wrong. It's NOT for collaborative file management.