Steam Frame pricing and release date revealed by Valve - it's a lottery again
(www.gamingonlinux.com)
Let's say they removed the onboard capability, and doing so halved the price.
You're then left with a device which costs basically the same as a Quest 3 but also requires a PC to do anything. I'm pretty sure that would be reviewed a heck of a lot worse than even the current situation is.
A self-contained unit that matched the Quest and wins on not price but privacy was the only reasonable direction for Valve here.