A quick recap of how it works: Viewers have the opportunity to hype up to three videos per week for a creator with under 500,000 subscribers. When a video is hyped, it receives points, giving it a chance to end up on a new ranked leaderboard that you can find in the Explore menu. To level the playing field, hype gives smaller creators a bigger boost. The fewer the subscribers, the bigger the bonus, giving the most authentic emerging creators a better opportunity to get noticed.
Source: YouTube Official Blog.
It helps YouTube also, which is probably the only reason why they’re doing it. The more that views are concentrated in a small number of creators, then then more power those video creators have. By spreading views across a greater number of creators, YouTube can retain more control/money