There is more than one benefit to ending physical media.

1. The end of the resale market
2. The end of paying for physical distribution.
3. Pushing users toward online gaming so that they can pay for microtransactions.
4. Live service games and seasons that require a subscriptions.
5. The sale of hardware that will allow them to charge more for consoles/Harddrives.
6. Game streaming (which requires an internet connection, and allows them to gather information about users).
7. Game streaming that requires a whole separate online subscription.

If you thought it was just about the resale market I have some public landmarks for sale.