If my webpage loading makes ten database calls, and each database call takes 45 milliseconds, my webpages takes 300 milliseconds longer to load than if each call only took 15 milliseconds. 0.3 seconds across each page load, especially if the rest of the call is less than a second, can significantly improve the usability of a website and increase user retention. This applies for any user facing website whether its a social media platform, an online shop, or just a blog.

Obviously there are other improvements that can be made too, like batching db requests or in-memory caching, but this is one option.