As far as publishers are concerned, the single greatest cancer they face is the resale market. When a store sells a new game for £60, the publisher makes about £20, and the store gets between £15-20, depending on how they choose to price it. The rest is the cost of manufacturing and shipping. (These are rounded estimates, it varies)
Then, a week later, when someone trades that game in and the store resells it for $40, they get all of that, and the publisher gets nothing.
From their perspective, that’s basically theft, which is why they’ve been trying for decades to put a stop to it, which they can’t, or at least make more money from secondary sales by bundling single-use codes for “bonus” content that really should be part of the main game, which people who buy preowned will have to shell out extra for.
So that’s what getting rid of physical media is all about. If they get rid of the discs and cartridges, that market vanishes.
Please don’t mistake this explanation as an excuse. All of the platform holders have had the means to kill off the retail market and usher customers onto their digital storefronts for at least a decade. All they had to do was pass on even a fraction of the savings they make selling digitally, which cuts out the manufacturing, shipping, and retailer costs, onto the customer. But they haven’t. Games cost the same on the Playstation Store as they do on the Gamestop Shelf. Sometimes more!
They could have used the carrot, but pure greed means they’re now opting for the stick.


Used games held the console market in balance. You knew if you didn’t like a game, you could trade it and get something back, or at least buy a cheap used copy if you weren’t sure on a title.
The PC game market is kept in balance by constant discounting and availability. You manage risk by saying “I’ll wait a few years and get it for $4.98 instead.”
The presence of secomdary sellers (Fanatical, Humble Bundle etc) and even distinct markets (GoG, itch, service games that sell through their own accounts) means Steam still doesn’t have the same market-defining power Sony will in a post-disc world.