How to Completely Disable Comments in WordPress

add_action('admin_init', function () {
    // Redirect any user trying to access comments page
    global $pagenow;
     
    if ($pagenow === 'edit-comments.php') {
        wp_safe_redirect(admin_url());
        exit;
    }
 
    // Remove comments metabox from dashboard
    remove_meta_box('dashboard_recent_comments', 'dashboard', 'normal');
 
    // Disable support for comments and trackbacks in post types
    foreach (get_post_types() as $post_type) {
        if (post_type_supports($post_type, 'comments')) {
            remove_post_type_support($post_type, 'comments');
            remove_post_type_support($post_type, 'trackbacks');
        }
    }
});
 
// Close comments on the front-end
add_filter('comments_open', '__return_false', 20, 2);
add_filter('pings_open', '__return_false', 20, 2);
 
// Hide existing comments
add_filter('comments_array', '__return_empty_array', 10, 2);
 
// Remove comments page in menu
add_action('admin_menu', function () {
    remove_menu_page('edit-comments.php');
});
 
// Remove comments links from admin bar
add_action( 'wp_before_admin_bar_render', function(){
    global $wp_admin_bar;
    $wp_admin_bar->remove_menu('comments');
} );