> Maybe Matrix it is then, but it’s not very suitable for airgapped company-wide deployment
Element is literally built for airgapped company-wide deployments - this is precisely what https://element.io/server-suite is? It was originally built to install onto SIPRnet; it's been airgap-first since day 1.
Matrix is the protocol, so doesn’t do implementations (just like w3c doesn’t do web servers any more). But the distribution from Element indeed is self-host first, and doesn’t break stuff if you’re airgapped. The paywall (such as it is) is that features which empower the enterprise over the user are paid, whereas one which empower the end-user are FOSS.
Element is literally built for airgapped company-wide deployments - this is precisely what https://element.io/server-suite is? It was originally built to install onto SIPRnet; it's been airgap-first since day 1.