This adds libraries conditionally in d8

ashok.info.yml

name: 'Ashok Test'
type: module
description: Test loading libraries conditionally
core: 8.x

ashok.libraries.yml

ashok_library_one:
  version: 1.0.1
  js:
    ashok_js_one.js: {}
  dependencies:
    - core/jquery
    - core/drupal
    - core/drupalSettings
ashok_library_two:
  version: 1.33.7
  js:
    ashok_js_two.js: {}
  dependencies:
    - core/jquery
    - core/drupal
    - core/drupalSettings

ashok.module

<?php

/**
 * Implements hook_page_attachments().
 */
function ashok_page_attachments(array &$page) {
  // Load the library on every page.
  $page['#attached']['library'][] = 'ashok/ashok_library_one';
  $current_path = \Drupal::service('path.current')->getPath();
  $path = '/node/1';
  // Load the library on every page BUT '/node/1'. This is an explicit path.
  if (!\Drupal::service('path.matcher')->matchPath($current_path, $path)) {
   $page['#attached']['library'][] = 'ashok/ashok_library_two';
  }
}

ashok_js_one.js

console.log('This is js 1');

ashok_js_two.js

console.log('This is js 2');