@babel/plugin-transform-regexp-modifiers transforms unsupported RegExp modifiers to equivalent, compatible patterns. This is useful for targeting older JavaScript environments that lack features like the 's' (dotAll) flag or the 'v' flag. By rewriting regular expressions, the plugin ensures broader compatibility and avoids runtime errors, enabling developers to utilize modern RegExp syntax while maintaining support for legacy browsers and runtimes. The plugin optimizes the transformations for performance.