I think the better way to ask this question is “why do physical games not cost more than digital copies.”
Nowadays the majority of game sales are digital, which means that publishers are going to set prices so that they can sell a digital game with an optimal profit. According to this article, physical retailers cause price parity because raising the price of physical copies would cause them to not stock your game (which would of course open shelf space to other publishers). In all likelihood, physical copies will go up in price once they are only stocked by niche retailers and/or online distributors (who don’t have the shelf space issue since most folks already know what they want by the time they browse Amazon).
I think the better way to ask this question is “why do physical games not cost more than digital copies.”
Nowadays the majority of game sales are digital, which means that publishers are going to set prices so that they can sell a digital game with an optimal profit. According to this article, physical retailers cause price parity because raising the price of physical copies would cause them to not stock your game (which would of course open shelf space to other publishers). In all likelihood, physical copies will go up in price once they are only stocked by niche retailers and/or online distributors (who don’t have the shelf space issue since most folks already know what they want by the time they browse Amazon).