I wish people stopped spreading misinformation like this.
No the controller works for any game, outside of steam, without steam launched.
The only restriction is that to configure the controller, you need steam.
Otherwise, you can select a profile for desktop use that is mkb or a generic gamepad, and run your games through that. Of course, you won't have many of the modern features, since XInput does not support anything fancy. Want these features on your controller (not just the steam one, the 8bitdo, the switch 1/2, etc..) you will need modern input API... which are provided by Steam!
There was and probably will be third party applications to configure the controller outside of Steam. It is NOT a walled garden at all and imo, the best of both world.
This contradicts all reviews I've read, but good if true.
> No the controller works for any game, outside of steam, without steam launched.
Can you provide any evidence for this claim?
To be frank, it sounds like you are also spreading misinformation. In a follow-up you even said that you have not received yours to test and that you are only assuming based on the previous steam controller.
But your comment here is very definitive and is a major problem at how quick we are to defend Valve when we don't actually know.