Well, however one looks at it, there are 7700/64000 assets are on sale right now. And only 2200/1050000 games are on sale.
Any addiational attention to a project is much higher for a game, than it is for assets, because of a sale. And if the sorting is popularity based, you need to be known and popular to benefit from this. Or be already on collections so people looking for items on sale on their collections will be reminded of your projects.