I don't understand how they imagine the business usecase around this and build these products which are almost negligible In real world, I need a system which

I don't understand how they imagine the business usecase around this and build these products which are almost negligible In real world, I need a system which must be writing data into parquet files. If such system exist, why would I ever choose Postgres to query. I can pretty much use same data lakes/systems which are writing the data to query the data. If I want to scale horizontally, I would use something like duckdb for in-process or even simpler solutions instead of eating the transactional database process workers.