If Valve prefers not selling games in the EU to implementing a way to sell second hand games, sure.
Remember that the French court is referencing EU law. This basically means that the practice is forbidden across the entire EU based on current jurisdiction.
It's possible for Valve to introduce pay-as-you-go games, but doing so would probably violate the contract under which previously sold games were sold. This means that they still need some way to allow customers to either resell or download and resell the old games regardless of whether they will charge a fee to their users or not.
They might also undo the sale of the old game, assuming the customer agrees to do that, and give back the entire paid amount spent on the platform in exchange for removing the old games. This would be a huge financial loss to the company and would only be possible if all customers agree to getting their money back.
If they do charge a fee, they should expect their consumer base in Europe to shrink significantly.
If Steam wants to appeal, they might be able to put the case in front of an EU judge. This will cost them even more legal fees and is likely to end in the same result. Reselling digital goods is allowed in the EU and Valve (as well as other companies like it) are breaking the law.
In my opinion, just following the law would be a better choice commercially than trying to work around it.
Would valve be legally required to offer their services (game download + cloud saves) to a second hand buyer? Surely the person selling the game would need to provide the second hand buyer the copy of the game along with the key?
Valve merely provides a service which says "this key now belongs to this account" but that second hand buyer has no right to download from valve?
I'd say yes. The steam key comes with a set of perks that made the buyer pick steam as a reseller over one of their competitors. Removing those features would degrade the value of the product and, in my opinion, be a measure to prevent proper resale of the product.
When I buy a key, I don't somehow get the download to my computer before adding it to my Steam account. Steam designed their system in such a way that the installer has to come from them, and that you can't burn an installer that only works with your key.
Imagine buying a chair with massage functionality and a GPS tracker that stops working when you move it outside your house. In my opinion, even though the chair itself remains functional, the added DRM would prevent someone from selling the chair second hand, because the main reason you buy the chair has suddenly been disabled by a third party.
Remember that the French court is referencing EU law. This basically means that the practice is forbidden across the entire EU based on current jurisdiction.
It's possible for Valve to introduce pay-as-you-go games, but doing so would probably violate the contract under which previously sold games were sold. This means that they still need some way to allow customers to either resell or download and resell the old games regardless of whether they will charge a fee to their users or not.
They might also undo the sale of the old game, assuming the customer agrees to do that, and give back the entire paid amount spent on the platform in exchange for removing the old games. This would be a huge financial loss to the company and would only be possible if all customers agree to getting their money back.
If they do charge a fee, they should expect their consumer base in Europe to shrink significantly.
If Steam wants to appeal, they might be able to put the case in front of an EU judge. This will cost them even more legal fees and is likely to end in the same result. Reselling digital goods is allowed in the EU and Valve (as well as other companies like it) are breaking the law.
In my opinion, just following the law would be a better choice commercially than trying to work around it.