Why can’t I display anything on the product page? product.info.main

   app/module/vendor/View/layout


   <?xml version="1.0"?>
   <page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  
     xsi: 
     noNamespaceSchemaLocation=
    "urn:magento:framework:View/Layout/etc/page_configuration.xsd">
     <body>
      <referenceBlock name="product.info.main">
        <block class="SegaProductHeightBlockProductHeight" 
     template="Sega_ProductHeight::height.phtml" cacheable="false"/>
     </referenceBlock>
    </body>
    </page>

app/module/vendor/View/template

test

module/vendor/Block

   <?php
   namespace SegaProductHeightBlock;

    use MagentoCatalogModelProduct;
    use MagentoFrameworkExceptionLocalizedException;
    use MagentoFrameworkRegistry;
    use MagentoFrameworkViewElementTemplate;

    class ProductHeight extends Template
    {
  
    protected $registry;

 
    protected $product;

    public function __construct(
    TemplateContext $context,
    Registry $registry,
    array $data)
  {
    $this->registry = $registry;

    parent::__construct($context, $data);
  }

 
     public function getProduct()
    {
    if (is_null($this->product)) {
        $this->product = $this->registry->registry('product');

        if (!$this->product->getId()) {
            throw new LocalizedException(__('Failed to initialize product'));
        }
    }

    return $this->product;
}

public function getProductHeight()
{
    return $this->getProduct()->getData('product_height');
}
}