I didn’t realize the new Steam family sharing was so detrimental to close ones away from each other. Their Guide & FAQ is clear with their intentions:

While we know that families come in many shapes and sizes, Steam Families is intended for a household of up to 6 close family members.

To that end, we expect the requirements for participating in a Steam Family to change over time as we monitor its usage and add requirements to keep usage in line with this intent.

Last line is pretty brutal. Apparently even family members living in the same country & different household might be in for a surprise eventually. That’s really saddening because at first glance this overhaul sounded amazing considering a single game was locked by play instead of the whole library.