I already own a Chromecast Ultra. Why would I want to pay for another one? I have no idea why I can't buy a controller by itself for $69. It will be interest

I already own a Chromecast Ultra. Why would I want to pay for another one? I have no idea why I can't buy a controller by itself for $69. It will be interesting to see how they treat paying customers when they inevitably shut this thing down.