It’s possible to make fewer requests without negatively impacting the user experience. For example, batching requests would result in a more responsive app.
He specifically cited situations where the opposite is true - for example when first opening a subreddit, he requests only 25 posts so the UI can render something quickly, then requests a further 100 posts to prepare for the user scrolling.
He could just request 100 posts first, halving the API requests, but the app would be less responsive.
Your comments seem to have a confidence level that their content doesn't justify.
That’s a great example of something that could be optimized without impacting the user experience. For example, just request the next page of posts when the user starts to reach the bottom. The reason for my confidence is that I’ve worked with Reddit’s API before and I know exactly where the pitfalls are.
That’s too late to be sending the request if you want the premium feeling of no loading times while scrolling, especially if you also want to do rich thumbnails of media.
He could just request 100 posts first, halving the API requests, but the app would be less responsive.
Your comments seem to have a confidence level that their content doesn't justify.