You are right, that setting up a modern #XMPP server has some "funny" aspects: You need the right DNS entries, you want to have an HTTP server, and there is #TURN for #Jingle.
But I didn't understand the post by @frankie in the way, they were promoting selfhosting.
For most "non-geek" people I suggest (for #Jabber as for email or fediverse/Mastodon) to select a trustworthy server. E.g. a local internet club, a cooperative or a small company. There are many free and paid options.