@xmpp a protocol alone does not allow you to instant message. It requires an app. One that your grandma can use. Xmpp and matrix apps are a very hard sell, even with the most technical crowd.
The author tried to point out some more general thoughts on this discussion. Technology is hard for many people, no doubts. However, no one is helped to blindly switch messengers all the time.
At the end of the article various links has been provided, see this one for example:
Fosstodon is an English speaking Mastodon instance that is open to anyone who is interested in technology; particularly free & open source software.