systemd-homed is not about encryption of the home directories. That’s only one of the things it offers as a “bonus”. What it’s really about, is the creation of a stateless machine, so that all machine- and user-specific settings are uncoupled from the actual operating system, and thus become portable across different machines without requiring any extra configuration.
While this may all seem like a good idea for certain corner cases, it is generally considered a bad idea for most other implementations. For starters, it wouldn’t work on servers, because logins over
ssh would no longer be possible in the traditional sense, given that the
ssh keys would no longer be stored in the operating system of the machine, but in the home directories. And that, then, creates a chicken-and-egg situation.