Le Quadrature du Chat / What I want for team chat:

* Interface like Slack or Discord
* Voice Call quality like Discord
* Screenshare quality like Discord (allows you less fps for higher screen resolution / readability)
* video call optional
* federated like matrix
* open source but with reasonable commercial pricing and hosting options
* if commercial, no US company - preferably EU or local hosters like Hetzner can offer it as SaaS
* not implemented with scripting language
* encrypted / secure