[PurpleRamen]

[..]Real time collaboration systems such as Microsoft Teams, Slack, Mattermost, Wire, Threema, WhatsApp and Signal are currently all closed proprietary systems - meaning they are walled gardens whereby all parties have to use the same vendor. That’s impractical, creates vendor lock-in and stifles innovation. There’s simply no way that a government entity using, say, Microsoft Teams would be able to have secure real time communication with another government entity using, for example, Slack, Mattermost or Wire.[..]