games companies often have internal discord servers since they generally have a public discord server for players, so it keeps you in the same space. Plus when you screen share you can select between "full resolution, low frame rate" or "full frame rate, low resolution"; the full resolution at 5fps option is actually really good for pair programming. With that said, both game studios I worked at also had Slack and primarily used Slack.

Considering the rumblings about a near-term IPO for Discord I would be looking at alternatives yesterday.

I'm disappointed in the availability of self-hosted alternatives for personal use right now, but businesses don't really have an excuse.