probably not a huge deal, but bigger implications

Took a quick look at JSON Group Record and JSON User record from Systemd's documentation it all seems very reasonable and not any different then what people have already been doing for decades with LDAP.

It would be nice to have a nice way for users to set their picture, email address, timezone, default language, security keys, etc. in a saner manner. None of that seems crazy or undesirable.

And since systemd-userdb provides support for multiple backends then it can provide a unified interface for retrieving and interacting with LDAP and other sources of user information people already use and rely on while systemd-homed provides feature parity for people not using any of those services.

If it all works out then it should represent a nice improvement and simplification of the OS over the status quo.