We extensively use Apache Arrow to store data files as parquet files on S3. This is a cheap way to store data that doesn't require the query speed of a relational (or non relational database). The main advantage of Arrow is that is a columnar database, and loses no information in transit unlike the nightmare of CSV files.
I just did some benchmarks and it's pretty similar for small files. The difference would only be noticeable if you're serializing a ton of small files.