The Drupal source code doesn't look good.
Screenshot - https://instantcms.ru/upload/forum/d3c287acab06259e8fbfb255d60f51ef.png…
Drupal compresses html, css, and java scripts to optimize code.
Drupal is a content management system (CMS), virtually unlimited, that underpins many sites. With this system, you can create a website of any complexity, it is also convenient and often used as a framework of web-applications.
Here is a list of those who chose this system to create their sites.