If you are a WordPress front-end developer or a mobile developer that uses WordPress as a back-end service you would take a lot from Rest Routes. You can build your front-end applications using any framework of your choice (React, Vue, etc.) and then use Rest Routes to design the custom endpoints that they will consume without the need of touching PHP code for it.
This plugin is recommended for you that is developing WordPress applications that need to communicate with external servers. You can easily build custom routes that will both expose data to the third-party server and populate data into your WordPress application database.
If you are simply using the WordPress as a back-end application, which means that you are not using anything related to the front-end of the WordPress, such as Themes, then this plugin is fully recommended for you. You can easily build custom routes that will let you expose your back-end data and also populate existing database tables.