Fundamentally, the developer has a choice to encrypt or not encrypt the data stored. Remember, once data is committed to the public blockchain, anyone can forever see it. Therefore, even if you choose to use encryption, please use the strongest encryption you can to ensure the security of your sensitive payload.
In addition, some customers have found the process of encryption can work well at compressing the payload. As a result, a data compression step might be redundant.
The link below is an easy-to-use, offline tool to test the payload size of your data set.