Yup, I did use it like that. You found a flaw: I shouldn’t have said “never”. I actually did try it for maybe like 5mins and got felt meh about it.
It’s a nice enough controller tbh. It’s just so inconvenient compared to my wireless dualsense controller. Or any other controller: Xbox, dualshock4, steam, backbone controller connected to an iPhone etc.
The stadia controller is really nice in the sense that it has Google assistant built in yadda yadda. Imagine if they made that configurable to control Cortana on windows. Or some form or voice control on windows. It would make using my living room PC that much easier.
As I understand it, the Stadia controller can be used like a wired USB game controller on a PC.