Allow anonymous to view user profiles

Solution

Change on /mysite/public_html/profiles/contrib/social/modules/social_features/social_user/social_user.routing.yml this:

social_user.user_home:
  path: '/user/{user}/home'
  defaults:
    _entity_view: 'user.stream'
  requirements:
    _user_is_logged_in: 'TRUE'
    _custom_access: '\Drupal\social_user\Controller\SocialUserController::accessUsersPages'

social_user.stream:
  path: '/user/{user}/stream'
  defaults:
    _entity_view: 'user.stream'
  requirements:
    _user_is_logged_in: 'TRUE'
    _custom_access: '\Drupal\social_user\Controller\SocialUserController::accessUsersPages'

By:

social_user.user_home:
  path: '/user/{user}/home'
  defaults:
    _entity_view: 'user.stream'
  requirements:
    _custom_access: '\Drupal\social_user\Controller\SocialUserController::accessUsersPages'

social_user.stream:
  path: '/user/{user}/stream'
  defaults:
    _entity_view: 'user.stream'
    _title_callback: 'Drupal\user\Controller\UserController::userTitle'
  requirements:
    _custom_access: '\Drupal\social_user\Controller\SocialUserController::accessUsersPages'

This solution will allow the username to be displayed in the title and will give control over whether the stream is accessible to anonymous users.

But it will be erased during the update. I suggest that the developers consider this solution for inclusion in the next releases.