The same way you sell your disks: find a buyer, send them the game files, they send you the money

> find a buyer

this buyer would rather buy off GOG than you, unless you give a significant discount (and even then, the trust is hard to establish).

Therefore, even if you might have a legal right to re-sell (which you really don't unfortunately), the actual sale won't happen.

That's not relevant to the issue of "ownership"

Same for disks. That the second hand market is cheaper is expected and a feature and a major reason why game publishers do everything they can so it doesn't exist.

Just give them the files and pinky promise to delete them yourself?

Gog license doesn't allow reselling at all

Then you don't really own it IMO.

I agree. It allows you yo backup your games, which to be fair you can do with Steam too and just play offline forever.

It amazes me that people nowadays know so little about piracy that this is somehow touted as a solution.

GP wasn't being serious.

I've seen this sentiment repeated enough times on reddit that I no longer can tell the difference.

This isn't an ownership problem, it's a medium problem (and perhaps a legal problem)