Retrieving product collection with all possible data in one call

I’m building a custom API endpoint which produces a product data dataset for a custom front-end application. All works fine, but I want to optimise the code, because I still have multiple database requests where I guess it should be possible in one request as well.

The collection factory produces a list of products, but in order to access the Extension Attributes and Media Gallery Entries, I have to load the product via the product factory, otherwise getExtensionAttributes and getMediaGalleryEntries always return null.

I found all kinds of additional instructions for the collection but yet nothing seems to bring the desired results. What am I missing? Or is there a completely different approach for this which gets better results (better performance)?

private $productFactory;
private $productCollectionFactory;

public function __construct(
    MagentoCatalogModelResourceModelProductCollectionFactory $productCollectionFactory,
    MagentoCatalogModelProductFactory $productFactory
) {
    $this->productCollectionFactory = $productCollectionFactory;
    $this->productFactory = $productFactory;
}

public function getList()
{
    $collection = $collection->addAttributeToSelect('*')->addFieldToFilter('status', ['eq' => 1])->setPageSize(10);

    $result = [];
    foreach ($collection->getItems() as $product) {
        $result[] = $this->processProduct($product);
    }

    return $result;
}

private function processProduct(ProductInterface $product)
{
    //build my own api response item
    $responseItem = $this->responseItemFactory->create();

    //retrieving sku and other basic properties works fine
    $sku = $product->getSku();
    //retrieving custom attributes also works fine
    $customAttributes = $product->getCustomAttributes();

    //these don't seem to work
    $extensionAttributes = $product->getExtensionAttributes();
    $mediaGalleryEntries = $product->getMediaGalleryEntries();

    //this is my current workaround
    $fullProduct = $this->productFactory->create()->load($product->getId());
    //and fullProduct does give me ExtensionAttributes and MediaGalleryEntries

    //.....

    return $responseItem;
}