babel-plugin-syntax-trailing-function-commas enables Babel to parse trailing commas in function parameter lists and calls. This plugin, crucial for projects targeting more modern JavaScript environments, adds syntax support without transforming the code. It allows developers to use trailing commas for improved code readability and easier diffing, especially in large function declarations or calls. This ensures future compatibility with features that readily support trailing commas. Using this plugin paves the way for cleaner, modern JavaScript development.