DuckLake is more comparable to Iceberg and Delta than to raw parquet files. Iceberg requires a catalog layer too, a file system based one at its simplest. For DuckLake any RDBMS will do, including fs-based ones like DuckDB and SQLite. The difference is that DuckLake will use that database with all its ACID goodness for all metadata operations and there is no need to implement transactional semantics over a REST or object storage API.