For starters, 20% to the platform(a little part for steam for being the middle man and a part for the developers) in the reselling to maintain their gains a little, with the possibility of givin it for free outside the platform to a friend or selling in other places like amazon, ebay or something.
That would be a good way to go, it might damage or make it hard but it also incentivate creators to do a better job and well more jobs v:
More games, to lower prices now and them to beat the resselers
And free games may come with a clause that you cant resell without the platforms (that gave it for free) consent or something, after all changing the market wont break it, for instance, it was different when digital copies started but we addapted and was for the best why cant we do it again!?
Fear of games like rock simulator dissapearing!? Or developers putting an extra effort!? If thats the problem then make it only sellable after a year of the launch or after owning it for a year or a few months..
Could be aclause you sign when you buy and trully needs to accept so you can’t cry later
After all its their platform, you are just a user.
You cant demand them to lose just for you to gain something and be abble to abuse the system..
Anything works if you make it right, accessible and fair to All sides..