How can I Remove user access to the contents of WordPress admin menus?

Solution:

By WP_Role we can easily update the role by removing or adding new capabilities. Bellow a sample example for user role Administrator.

WP_Roles => array(
  'roles' => array(
    'administrator' => array(
      'name' => 'administrator',
      'capabilities' => array(
        'switch_themes' => true,
        'edit_themes' =>  true,
        'activate_plugins' => true,
        // Much more
      ),
      // Other roles
    ),
   'role_names' => array(
    'administrator' => 'Administrator',
     // Other role names
   )
   // ...
 );

You can get full understanding to go through official documents.

Here is the link of official documents of WordPress Role and Permission. https://developer.wordpress.org/plugins/users/roles-and-capabilities/