This is a convenient option for people who own a Xbox, and like using the Xbox web browser.
Paying to use Geforce Now service on a Xbox web browser may not be very worth it for some people. Some subscribers could end up spending more money subscribing to Geforce compared to playing regular Steam games on a PC, and connecting their PC to a TV with a HDMI cable.
I tried this yesterday. The XBox browser is shit but I tried it on my main laptop and it works wonders. So if you don't have a powerful pc or laptop but still wanna play certain Steam games (or even PC Game Pass), this would be the way to go.