If there are too many elements, the component news.list may significantly slow down the generation of a page. The component must be optimized. You may consider deleting the link to the detailed news text in the preview description as one of the optimization options (a link with the name of the news will remain).
Copy the component to the namespace (/bitrix/components/my_components/).
Delete the following lines in the code of the component copied (/bitrix/components/my_components/news.list/component.php):
Save the changes made.
Apply your own component instead of the standard on.
As a result, there will be more database queries but the page will be formed faster.