The modern approach to file formats is to use JavaScript Object Notation (JSON). It was specifically developed for interpretation by JavaScript coding, typically in a website. For example, a web page needs a list of products and asks for that list from the web server coding. The web server coding responds with the information encoded in JSON format, knowing that JavaScript resides in the web application and can easily interpret the information.
As it became more popular to use JSON on web applications, many realized it was a robust data format supporting hierarchical structures without having to resort to the flattening required by CSV. People then started using JSON in a variety of applications, not just website intercommunication.