Obviously a new user is not expected to fathom what all this means before getting started, which is why there are curated lists of public XMPP services, e.g. https://providers.xmpp.net/ and https://joinjabber.org/ and for private servers there are projects like Snikket where the server software is developed in parallel with apps to ensure a consistent feature set.
It's not: https://compliance.conversations.im/tests/
Obviously a new user is not expected to fathom what all this means before getting started, which is why there are curated lists of public XMPP services, e.g. https://providers.xmpp.net/ and https://joinjabber.org/ and for private servers there are projects like Snikket where the server software is developed in parallel with apps to ensure a consistent feature set.