It is complex than WordPress and Joomla. And it is almost certain that it is possible not to develop a website using Drupal as a beginner. The cost of hiring professional services could be higher than of Joomla or WordPress
Ease of use
More complex than wordpress and Joomla, it comes embedded with distributions. Although it allows complete control over the admin panel, it is not as easy to use as it is more complicated. It requires the user to learn a lot before becoming a professional in developing websites through drupal.
Highly documented for customer support. There are support groups or even third party blogs could help a user learn more on Drupal
Usually comes with customized templates and there is nothing user that cannot customize, the platform facilitates custom websites.
Its themes and plugins are almost compatible with each other unlike Joomla and WordPress. However their installation is more complex.
Less demanding on the servers and less resource intensive hence the fastest of the three.
It has extensions that supports caching hence faster page loads
There are more extensions available to make the site more secure. The support team responds quickly to security issues.
There are in built SEO practices and the availability of plugins that makes it easier to do SEO with Drupal.
Suitable for sites with unlimited customization and have extensive features. Not suitable for beginners