Beyond the Steampipe CLI (which has an embedded Postgres), you can use the steampipe plugins as native Postgres FDWs [1], SQLite extensions [2] or command line export tools [3]. We're definitely interested in bringing the plugins to duckdb as well, but haven't had a chance to focus there yet!
1 - https://steampipe.io/blog/2023-12-postgres-extensions 2 - https://steampipe.io/blog/2023-12-sqlite-extensions 3 - https://steampipe.io/blog/2023-12-steampipe-export