You know if I used a computer for anything, yeah maybe but my desktop gets nearly zero use. Just Legacy stuff like playing an occasional optical disk or running super old dos programs.You sure you won't get a nice FPS boost in Alyx with a cheap i5-12400 upgrade?
The laptop with the 1660ti sees some gaming and VR support duty and everything else happens on phones which are remarkably competent and convenient. DeX allows the use of a keyboard, mouse and monitor or TV with the phone.
A shiny new desktop with a 3070 would take over the VR support role, headless most likely. The computers are all horribly inconvenient compared to the phone. The 3070 system would sit doing nothing after finishing Alyx.