I tried it, and still have it running on a little toy service I built. It's cool, but IMO, it doesn't really seem production-ready for a large-scale service. Last time I updated it, I had to spend a full day sorting out the changes they made to how the server config and user authentication works. Last I checked, they don't even have a suggested script to run it as a service. Going by the contributor graph, it's still essentially a 1-person project.
IIRC, this was what the connection poolers (pgpool, pgbouncer), and perhaps all now-popular postgres extensions/enhancements, looked like in their initial years, as well.
In the context of a "large-scale service", my guess is that there's a chicken-and-egg problem, where an operators of such a service has to decide they want it to be production-ready enough to throw money and/or engineering resources at the project, which can attract yet more contributors.
