Useful Wordpress setup

actions.php

 add_action( 'init', function() {

     // Remove the REST API endpoint.
     remove_action('rest_api_init', 'wp_oembed_register_route');

     // Turn off oEmbed auto discovery.
     // Don't filter oEmbed results.
     remove_filter('oembed_dataparse', 'wp_filter_oembed_result', 10);

     // Remove oEmbed discovery links.
     remove_action('wp_head', 'wp_oembed_add_discovery_links');

     // Remove oEmbed-specific JavaScript from the front-end and back-end.
     remove_action('wp_head', 'wp_oembed_add_host_js');
 }, PHP_INT_MAX - 1 );

// REMOVE WP EMOJI
remove_action('wp_head', 'print_emoji_detection_script', 7);
remove_action('wp_print_styles', 'print_emoji_styles');
remove_action( 'admin_print_scripts', 'print_emoji_detection_script' );
remove_action( 'admin_print_styles', 'print_emoji_styles' );

disable-comments.php

<?php
/**
 * Plugin Name: Disable Comments
 * Plugin URI: https://gist.github.com/danfoust/72742429a74d5a691cd1f2db064ce620
 * Description: A must-use plugin that disables comments everywhere
 * Version: 1.0.0
 * Author: Daniel Foust
 * Author URI: https://foustwebdesignllc.com
 * License: MIT License
 */

// Disable support for comments and trackbacks in post types
add_action('admin_init', function () {
    $post_types = get_post_types();
    foreach ($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');
        }
    }
});

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

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

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

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

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

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

filters.php

// Disable Attachment Pages Completely
add_filter('rewrite_rules_array', function ($rules) {
    foreach ($rules as $regex => $query) {
        if (strpos($regex, 'attachment') || strpos($query, 'attachment')) {
            unset($rules[ $regex ]);
        }
    }

    return $rules;
});

// Remove admin attachment page pretty URLs in media library
add_filter('attachment_link', function () {
    return;
});

/**
 * Disable jQuery Migrate in WordPress.
 *
 * @author Guy Dumais.
 * @link https://en.guydumais.digital/disable-jquery-migrate-in-wordpress/
 */
add_filter('wp_default_scripts', function (&$scripts) {
    if (!is_admin()) {
        $scripts->remove('jquery');
        $scripts->add('jquery', false, array( 'jquery-core' ), '1.12.4');
    }
}, PHP_INT_MAX);

/**
 * Use Lozad (lazy loading) for attachments/featured images
 */
add_filter('wp_get_attachment_image_attributes', function ($attr, $attachment) {
    // Bail on admin
    if (is_admin()) {
        return $attr;
    }

    $attr['data-src'] = $attr['src'];
    $attr['class'] .= ' lozad';
    unset($attr['src']);

    return $attr;
}, 10, 2);