What does it even mean to “own” a video game?

[BraLoD]

Chrkeller said:

Wman1996 said:

And that's the kicker. Digital would be amazing with almost no faults if you could back it up. There are not many legal opportunities to do so. 

Steam has an entire backup system built in.  I have backup copies of my digital games.  A few clicks and my entire library is on a secondary drive.  

If Gabe decided he likes boats so much that he would like to spend every single penny on buying as many of them as possible and Steam would be permanently shut down today, how many of these backed up games would still work without going thorugh Steam client tho?