rqlite is very cool, but I have a hard time thinking of a real world use case.

For a project where sqlite is good enough, just using it plus the amazing sqlite rsync command on a cron job gives you pretty amazing capabilities.

When/if you outgrow that and/or need something more, like GIS capabilities, Postgres is the choice.

rqlite sits somewhere between, and I'm not sure how I'd actually use it?