I don't think this is a competition, but to clarify: XMPP has long been used in the public sector (via suppliers such as Isode) since before Matrix was conceived, and continues to be still. I've spoken with multiple organizations for whom the Matrix data model was not a good fit. As you say, they are quite different and each has strengths and weaknesses.
Yup - XMPP clearly has a lot of public sector traction too (e.g. in NATO's Federated Mission Networking), and each protocol has its merits. I was just trying to explain that the current "how can Governments better fund Matrix" is borne out of a glut of Governmental Matrix deployments as a WhatsApp/Teams replacement.
The OP is calling out the need for any large org that depends on a FOSS project to contribute to its maintenance.
Currently we don’t have good mechanisms to make this happen.
The post uses Matrix as an example but it applies equally to any project deemed as critical infrastructure which would of course include XMPP, IRC and plenty of others.
To solve this, FOSS projects must work together to advocate for practical funding mechanisms. This is not a zero sum game.
