I have the same thoughts. However my impression is also that most orgs would choose eg databricks or something for the permission handling, web ui, ++ so what is the equivalent «full rig» with duckdb and S3 / blob storage?
For the ETL side, where often whole-table access is good enough, I find Spark in particular very cumbersome - there's more than can go wrong vs. DuckDB and it's harder to troubleshoot.