String placeholders explanation
@variable: When the placeholder replacement value is:
A string, the replaced value in the returned string will be sanitized using \Drupal\Component\Utility\Html::escape().
A MarkupInterface object, the replaced value in the returned string will not be sanitized.
A MarkupInterface object cast to a string, the replaced value in the returned string be forcibly sanitized using \Drupal\Component\Utility\Html::escape().