Cancel culture is making self-hosting more important than ever. Using 3rd party servers waives 4th amendment rights in the US, and hosting Companies in the US have shown that they put their political preferences ahead of formerly sacrosanct customer data access and privacy.
Matrix is an open protocol, and most implementations are open source¹. You are not dependent on a single corporation.
Because Matrix is an open standard, many client implementations are available: web apps, desktop apps, phone apps for pretty much every OS.
Several homeserver implementations are available as well. This homeserver is running the Synapse package written in python3 and running on the Fedora 36 linux OS.
¹ Nothing precludes a proprietary implementation.