I think only gamestop really cares in the united states.
Target would be fine selling cardboard and getting $5 bucks a pop for them. Think about how many game cards you can fit in the same space as a single copy of a game. 10 or 15 of them I'd think or very close to it. Then there is no need for the security set ups they have now. Since the cardboard is worthless .
I think towards the end of the generation a lot of big stores will have these for the xbox one while stores like gamestop will still stock discs
The people that opt for these game cards will simply go DD and ignore these cards altogether, so in that case the stores like Target will still need to stock some disks.