In principal, I agree. I'm certain Slack has run the numbers and decided the ROI of implementing cross-browser video calling is lower than whatever else they're

In principal, I agree. I'm certain Slack has run the numbers and decided the ROI of implementing cross-browser video calling is lower than whatever else they're investing engineering time into. Sure, they have a lot of capital, but it's a large undertaking. A vocal minority of Twitter users shouldn't sway this. In practice, it's pretty lame that they've had voice calling for almost two years, and this has never been available in Firefox. We're not talking about old IE here. A basic implementation of voice only calling is not hard to do.