Great question - and I agree that it is a bit unclear as to which benefit you are giving up. The benefit would be using multiple parquet files for increased performance.
See https://stackoverflow.com/questions/27194333/how-to-split-pa..., https://parquet.apache.org/documentation/latest/, etc.
Whether it's better to have multiple Parquet files or a single parallelizable Parquet file is dependent on your environment and application. At my company, we've tended to have a single row group per file (and one HDFS block per file), in part due to historical reasons.
The way "normal" (non-HDFS) tools write data is by creating a file with an extension. Let's say you have a 2GB parquet file, if it's broken down into 4 smaller positions, your read rates will likely be quicker, especially if the file is distributed.