I would bet most PlayStation owners play online games and subscribe to PlayStation+ so I don't think you're describing a future state here so much as the current one.
Online purchases in some fashion are delivered to you and put on your hard disk. You can in theory preserve the game or reverse engineer it when its constituent parts have to be delivered to you.
Online-only DRM is bad yeah, but with sufficient effort it can be sidestepped : see the unofficial WoW servers.
Meanwhile game streaming is extremely resource heavy, needs rock solid Internet connections, and runs into laws of physics for latency issues. But more games will probably go this route, yeah, especially those targeting players of specific (high) wealth brackets. (Boycott them, just like other online-only DRM.)