You can do calls within yes, both audio and video. Although starting up the app and syncing with the servers is always eternal. 🙃 
You almost have time to go grab a coffee in between you launch the application and it loads 😭 

 But if you are interested in doing audio chat and screen sharing, we’ve been keeping tabs on the development of @BITKARROT ‘s hivetalk.org which seems pretty cool shit :) 🤙 

 Thanks, will check it out 

 Is the same idea as...

Mattermost
Zoom
Teams
Slack
Nextcloud Talk