

Ok, I didn’t downvote you, but…
Its a Steam Controller.
For Steam.
… If you just made up some expectation, contrary to everything that Valve has said about this thing, and marketed it as…
To a certain extent, that is magical thinking, that is abandoning any concept of checking your hopes or expectations against… reality.
If you… want to run… a game… with this controller…
You install Steam, and the game.
Steam is the drivers, for the controller.
If you own the game in a way that you can’t add it to Steam… sorry about your DRM, I guess?
The Steam Controller has always been described by Valve as an evolution of the Steam Deck tech, both hardwsre and software… it pretty much literally is a Steam Deck, without the screen and PC, in a different shape.
EDIT:
IRT to your edit:
Point 1: Correct. The Steam Controller… works through Steam.
Point 2: … I don’t think the first half of this is correct. I’m not 100% sure, but I think you can do this via Moonlight/Sunshine. I mean… I know you can in general stream Steam games from a PC using Moonlight/Sunshine, I’m not 100% sure this will work with a Steam Controller… but it works on a Steam Deck, so… probably will work.
As to the second half of this… yeah, the Steam Controller probably won’t generally work as a controller for a game on a phone. Though FeX may actually somewhat/eventually aid with getting that to being possible.
Any projects? Make your project support Steam Input. I can’t speak for other engines too well, but Godot has GodotSteam, supports Steam Controllers, the SteamInput system.
As to your internet related concerns: Steam has an offline mode. Unless you are running a game via Steam that has its own/extra DRM that requires a constant internet connection, you’ll be fine.
SteamInput works without internet. If it didnt’t, a SteamDeck’s controls would not work at all without internet access. … It does.
EDIT 2:
Just for super duper clarity here:
Making a Steam account costs nothing.
Maintaining a Steam account costs nothing.
Any … .exe or .sh or whatever… can be added to Steam, to be launched and played via Steam.
The… only kind of situation where this wouldn’t work is essentially via a game that is installed/managed by some other platform that basically encrypts the exe in a way that only that platform can decrypt.
A GOG game, or something from Itch.io, with no DRM?
Plop it in Steam, it’ll work.



































… but the Steam Controller works with any hardware that can run Steam.
… which is… any PC, thats less than roughly 15-20 years old.
So this is absolutely not the exact same thing as what Nintendo does.
Steam is hardware agnostic. Nintendo is not.
You could run a Steam Controller on a Nintendo Switch, provided you got rid of Nintendo’s operating system, like so:
https://www.tomshardware.com/video-games/handheld-gaming/steam-shown-running-on-nintendo-switch-thanks-to-latest-proton-beta-fex-2604-translates-x86-to-arm-friendly-instructions-on-linux