There’s nothing more frustrating than the Comments section in WordPress, not only is it usually not needed it also clutters the WordPress Dashboard. Here’s some code to totally disable and hide Comments from the WordPress Dashboard.

function df_disable_comments_post_types_support() {
	$post_types = get_post_types();
	foreach ($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');
		}
	}
}
add_action('admin_init', 'df_disable_comments_post_types_support');

// Close comments on the front-end
function df_disable_comments_status() {
	return false;
}
add_filter('comments_open', 'df_disable_comments_status', 20, 2);
add_filter('pings_open', 'df_disable_comments_status', 20, 2);

// Hide existing comments
function df_disable_comments_hide_existing_comments($comments) {
	$comments = array();
	return $comments;
}
add_filter('comments_array', 'df_disable_comments_hide_existing_comments', 10, 2);

// Remove comments page in menu
function df_disable_comments_admin_menu() {
	remove_menu_page('edit-comments.php');
	remove_submenu_page( 'options-general.php', 'options-discussion.php' );
}
add_action('admin_menu', 'df_disable_comments_admin_menu');

// Redirect any user trying to access comments page
function df_disable_comments_admin_menu_redirect() {
	global $pagenow;
	if ($pagenow === 'edit-comments.php') {
		wp_redirect(admin_url()); exit;
	}
}
add_action('admin_init', 'df_disable_comments_admin_menu_redirect');

// Remove comments metabox from dashboard
function df_disable_comments_dashboard() {
	remove_meta_box('dashboard_recent_comments', 'dashboard', 'normal');
}
add_action('admin_init', 'df_disable_comments_dashboard');

// Remove comments links from admin bar
function df_disable_comments_admin_bar() {
	if (is_admin_bar_showing()) {
		remove_action('admin_bar_menu', 'wp_admin_bar_comments_menu', 60);
	}
}
add_action('init', 'df_disable_comments_admin_bar');

function remove_admin_bar_links() {
    global $wp_admin_bar;
    $wp_admin_bar->remove_menu('about');            // Remove the about WordPress link
    $wp_admin_bar->remove_menu('wporg');            // Remove the WordPress.org link
    $wp_admin_bar->remove_menu('documentation');    // Remove the WordPress documentation link
    $wp_admin_bar->remove_menu('support-forums');   // Remove the support forums link
    $wp_admin_bar->remove_menu('feedback');         // Remove the feedback link
    $wp_admin_bar->remove_menu('comments');         // Remove the comments link
}
add_action( 'wp_before_admin_bar_render', 'remove_admin_bar_links' );