I need to show all the newly created products on top. So need to arrange all the products according entity id in descending order
Easiest and cleanest solution would be creating an "afterPlugin" on
\Magento\Catalog\Model\Config\Source\ListSort::toOptionArray and adding
$options = ['label' => __('Entity ID'), 'value' => 'entity_id'];
Once you did this, you can select the value in "Configuration -> Catalog -> Catalog -> Product Listing Sort by" to apply it to all categories by default.