Do you have numbers to back that up or are you just speculating. Personally I’d find it weird that someone who games especially on a mobile platform with somehow have not heard of the steam deck. Between social media and targeted news feeds I don’t know how they not hear about it.
This is your notice that you are very much in a bubble. Most gamers have no idea what a steam deck is.
Most casual gamers. Also it depends on region. Steam marketed itself basically on steam only so the pc relevance as the gaming platform in your region really matters.