How to create reviews for user comments?
The scenario is not very encouraging for Drupal 8 in voting modules at this time, but you can check some modules that can help you:

Votingapi Widgets


  A flexible field based Voting System based on
  https://www.drupal.org/project/votingapi .


Like Button


  Add a Like button to Drupal content and comments! Get instant
  statistics and insights! Sort content by likes!


Star Rating


  Star Rating is a simple module that provides star rating field and
  display formatter using Drupal 7's Field Type API.