You don't need to use the official Stadia Controller if you want to use Google's game streaming service on your TV — or any dedicated controller, for that matter. Google is rolling out a feature that lets TV-bound Stadia players use their Android phone or iPhone as a virtual gamepad. You can also use third-party gamepads by connecting them to your phone through Bluetooth or USB.
The widened controller support requires Android TV, Google TV or a Chromecast Ultra. In most cases, you'll need to either add a controller or enable the touch gamepad through the Stadia mobile app, and promptly choose "play on TV." Android TV and Google TV owners will also need to enable a controller through the avatar section on the big-screen Stadia app.
This might help boost Stadia's adoption. While it has long given you the flexibility of where you can play, you haven't had many choices for that setup. It's now relatively easy to use a favorite gamepad with your TV or, if you prefer, save a little money and use no gamepad at all. It won't be perfect, however. A phone's touchscreen can only do so much, and using your phone as a go-between is bound to add a little latency.