Redirect 404 to Homepage

/**
 * Redirect all 404 pages to the homepage.
 * WARNING: This creates soft 404s which can harm SEO.
 * Only use this if you have a specific reason to do so.
 */
add_action( 'template_redirect', function() {
    if ( is_404() ) {
        wp_safe_redirect( home_url() );
        exit();
    }
} );