Back in the day, the guideline was to put useful information and links at the top of the page when it loads, so that people could read the important bits and follow the links they needed without having to scroll down. Then everyone started using the entire space on load for a stock marketing photo or video so you would always need to scroll to see anything useful. Then they added whitespace everywhere so you'd need to scroll more. Then they removed the scrollbars. And sometimes they make scrolling do unpredictable animations instead of scrolling. It has become self-indulgent design instead of functional.