Can someone explain where/why this might be used? Or is it just for fun?

First thing that came to mind was in one of the "Postgres-backend" projects like Hasura[1], Postgraphile[2], or PostgREST[3].

[1]: https://github.com/hasura/graphql-engine/

[2]: https://www.graphile.org/postgraphile/

[3]: https://postgrest.org