https://kotaku.com/french-court-says-valve-must-allow-steam-users-to-resel-1838259529Back in 2015, Valve got sued by a French consumer organization called UFC-Que Choisir (not to be confused with non-French, non-consumer organization the Ultimate Fighting Championship). UFC-Que Choisir had a multitude of bones to pick with the longtime Steam steward, the biggest among them being that Steam doesn’t let users resell their games. Four years later, a French court has ruled in UFC-Que Choisir’s favor. Valve plans to appeal.
Doesn't seem Valve is going anywhere with the appeal and it is just buying time since Oracle lost a similar lawsuit a few years ago.