Magento – Get the Attribute in details.phtml file on Product Page

You can get the value of custom attribute using following:

$attribute = $_product->getResource()->getAttribute('custom_attribute_code');
if ($attribute) {
    echo $attribute_value = $attribute->getFrontend()->getValue($_product);
}

I suggest you should use Magento\Eav\Api\AttributeManagementInterface to get all attributes by attribute set id

To do this, we need to override Magento\Catalog\Block\Product\ListProduct class and inject this class into the constructor. See more detail here:

1. app/code/YourVendor/YourModule/etc/frontend/di.xml

    <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <preference for="Magento\Catalog\Block\Product\ListProduct" type="YourVendor\YourModule\Block\Catalog\Product\ListProduct" />
</config>

2. app/code/YourVendor/YourModule/Block/Catalog/Product/ListProduct.php

use Magento\Catalog\Block\Product\Context;
use Magento\Catalog\Api\CategoryRepositoryInterface;
use Magento\Catalog\Model\Layer\Resolver;
use Magento\Framework\Data\Helper\PostHelper;
use Magento\Framework\Url\Helper\Data;
use Magento\Eav\Api\AttributeManagementInterface;

class ListProduct extends \Magento\Catalog\Block\Product\ListProduct
{
    private $attributeManagement;

    /**
     * @param Context $context
     * @param PostHelper $postDataHelper
     * @param Resolver $layerResolver
     * @param CategoryRepositoryInterface $categoryRepository
     * @param Data $urlHelper
     * @param AttributeManagementInterface $attributeManagement
     * @param array $data
     */
    public function __construct(
        Context $context,
        PostHelper $postDataHelper,
        Resolver $layerResolver,
        CategoryRepositoryInterface $categoryRepository,
        Data $urlHelper,
        AttributeManagementInterface $attributeManagement,
        array $data = []
    ) {
        $this->attributeManagement = $attributeManagement;
        parent::__construct(
            $context,
            $postDataHelper,
            $layerResolver,
            $categoryRepository,
            $urlHelper,
            $data
        );
    }

    /**
     * Get Attributes by Attribute Set ID
     * @param $attributeSetId
     * @return \Magento\Eav\Api\Data\AttributeInterface[]
     * @throws \Magento\Framework\Exception\NoSuchEntityException
     */
    public function getAttributesBySetId($attributeSetId)
    {
        $attributes = $this->attributeManagement->getAttributes(\Magento\Catalog\Model\Product::ENTITY,
            $attributeSetId);
        return $attributes;
    }
}

3. app/design/frontend/YourCustomTheme/templates/product/list.phtml

........
<?php $attributes = $block->getAttributesBySetId($_product->getAttributeSetId()); ?>
                <?php
                foreach ($attributes as $attribute) {
                    echo ($attribute->getFrontendLabel()).':::';
                }
                ?>
..........

Hopefully this will solve your issue

Regards