I can play NES games from 35 years ago despite the fact that Nintendo has ceased manufacturing the console and publishing the games.

As soon as Steam decides to shut down (and it will one day, be it tomorrow, or 30 years from now, those games are no longer playable).

Nothing lasts forever.

Except Valve could issue a final update that disables the DRM Check, and the game is still playable locally, right? More likely than Stadia developing a local client to sync game content/licenses to.

Valve doesn’t have the right to do this. They have an agreement with publishers that they will supply it.

They actually do have the right to do this and a technical implementation. Essentially they've escrowed enough cash to run the drm for many years in the future even if they went out of business so they keep their agreements and their customers happy.

Also, having worked in game sales, it turns out that buying "drm free unlocks of long tail" games is not expensive. How do you think things like PS Plus Free Games works? Essentially game devs book revenue now for possibl future revenue lost. It's a smart trade for most games unless that game is say skyrim.

Do you have a source for where Valve have the rights to remove DRM on third party games?

Also, PS Plus games are still DRM'ed, and you only have access as long as your subscription is valid.

Is there any sort of survivability clause in that agreement? Genuinely asking - not directly familiar with it.

If steam shuts down some cracker/hacker will find a way to disable the drm.

Almost every game has a pirated version in some torrent site.

Valve already promise that in the unlikely event the were to shutdown, they would cancel DRM on their platform game to become DRM free

That's not true. Not all games on Steam have the DRM requirement.

Doesn't that also apply to Netflix? If Netflix shuts down (and there is a real chance of that), what will happen? People will lose all those TV shows and Movies forever.

Yeah, but Netflix doesn't ask you for more money to see a movie on their platform. Whereas you do have to buy your own games on Stadia.

Maybe, but that wasn't the original argument I replied to.

To your argument I would say that Stadia is not the "Netflix for games". So I don't see why you expect to pay $10 and play any game you want like Netflix does.