Controller and chromecast is for console guys, we laptop owners can use mouse+keyboard + chrome browser to play.
But this will be available later, unless you want o throw $130 for just 3 months of Stadia Pro (and a controller+chromecast that will gather dust).
You need both to play at launch. Seems more like an early adopter tax - they could have just provided an update to the existing Chromecast Ultra and let you use a Bluetooth controller.
Heck, I'd shell out the $130 if was in the form of prepaid credit or something else. I don't want 2 more devices - and I'm not interested in playing on my TV.