The problem is, while Valve has balls of tungsten... MAFIAA et al have the money, much much more of it.

It makes a good underdog story, but unless Valve goes all-in and flashes a notification to every American Steam user "hey, write to your Congress reps to pass a law to fix this shit, and call their office every day until they publicly relent", no PR can force their hand. It took many years for Right to Repair bills to pass, and many of these only succeeded because the people pushing for it (aka farmers) are very well connected to their representatives and have very deep pockets of money.

The other solution is of course mass protests over civil disobedience to outright violence. That can work to force change as well, we've seen many a law changed in the past (most recently at scale during the Covid pandemic), but I don't see any big-tent movement going on against big-co extortion practices.