pcvr is the testbed for the standalone Quest. I imagine features will hit it first, be buggy as **** and then endup in the next generation quest. The quest is the reason FB bought oculus in the first place, it was always the goal.
DK1 -> DK2 -> CV1 ->quest
gearvr -> oculus go -> quest
Both product lines lead directly to the quest, where fb can get their billion users. But as long as pc's are faster and more flexible, FB is going to want to keep it around to push the hardware, before it's practical to bring it to a mainstream device. PCVR brought timewarp, space warp, touch, an ecosystem of 6dof dual controller games have have figured out what is actually fun to play. The lens technology, screen tech, software stack etc etc. Everything was a prototype for the Quest
valve/pimax/htc/wmr have saturated the market, and the daydream/vive focus are total flops. (though the vive focus is doing okay in china)
I hope fb eventually allows you to tether to the Quest and use it as a regular pcvr headset, but I imagine they'll wait until it's already solid in the market and turn it on as a "free" feature. The hardware can do it. It's got a better screen than the vive pro. Maybe they are waiting on a wireless attachment for next year @ OC6, they recently patented a device for a mesh network of wireless streaming to a headset.